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Access Token Theft and Manipulation Attacks – A Door to Local Privilege Escalation

20 April 2021 at 15:27
how to run a virus scan

Executive Summary

Many malware attacks designed to inflict damage on a network are armed with lateral movement capabilities. Post initial infection, such malware would usually need to perform a higher privileged task or execute a privileged command on the compromised system to be able to further enumerate the infection targets and compromise more systems on the network. Consequently, at some point during its lateral movement activities, it would need to escalate its privileges using one or the other privilege escalation techniques. Once malware or an attacker successfully escalates its privileges on the compromised system, it will acquire the ability to perform stealthier lateral movement, usually executing its tasks under the context of a privileged user, as well as bypassing mitigations like User Account Control.

Process access token manipulation is one such privilege escalation technique which is widely adopted by malware authors. These set of techniques include process access token theft and impersonation, which eventually allows malware to advance its lateral movement activities across the network in the context of another logged in user or higher privileged user.

When a user authenticates to Windows via console (interactive logon), a logon session is created, and an access token is granted to the user. Windows manages the identity, security, or access rights of the user on the system with this access token, essentially determining what system resources they can access and what tasks can be performed. An access token for a user is primarily a kernel object and an identification of that user in the system, which also contains many other details like groups, access rights, integrity level of the process, privileges, etc. Fundamentally, a user’s logon session has an access token which also references their credentials to be used for Windows single sign on (SSO) authentication to access the local or remote network resources.

Once the attacker gains an initial foothold on the target by compromising the initial system, they would want to move around the network laterally to access more resource or critical assets. One of the ways for an attacker to achieve this is to use the identity or credentials of already logged-on users on the compromised machine to pivot to other systems or escalate their privileges and perform the lateral movement in the context of another logged on higher privileged user. Process access token manipulation helps the attackers to precisely accomplish this goal.

For our YARA rule, MITRE ATT&CK techniques and to learn more about the technical details of token manipulation attacks and how malware executes these attacks successfully at the code level, read our complete technical analysis here.

Coverage

McAfee On-Access-Scan has a generic detection for this nature of malware  as shown in the below screenshot:

Additionally, the YARA rule mentioned at the end of the technical analysis document can also be used to detect the token manipulation attacks by importing the rule in the Threat detection solutions like McAfee Advance Threat Defence, this behaviour can be detected.

Summary of the Threat

Several types of malware and advanced persistent threats abuse process tokens to gain elevated privileges on the system. Malware can take multiple routes to achieve this goal. However, in all these routes, it would abuse the Windows APIs to execute the token stealing or token impersonation to gain elevated privileges and advance its lateral movement activities.

  • If the current logged on user on the compromised or infected machine is a part of the administrator group of users OR running a process with higher privileges (e.g., by using “runas” command), malware can abuse the privileges of the process’s access token to elevate its privileges on the system, thereby enabling itself to perform privileged tasks.
  • Malware can use multiple Windows APIs to enumerate the Windows processes running with higher privileges (usually SYSTEM level privileges), acquire the access tokens of those processes and start new processes with the acquired token. This results in the new process being started in the context of the user represented by the token, which is SYSTEM.
  • Malware can also execute a token impersonation attack where it can duplicate the access tokens of the higher privileged SYSTEM level process, convert it into the impersonation token by using appropriate Windows functionality and then impersonate the SYSTEM user on the infected machine, thereby elevating its privileges.
  • These token manipulation attacks will allow malware to use the credentials of the current logged on user or the credentials of another privileged user to authenticate to the remote network resource, leading to advancement of its lateral movement activities.
  • These attack techniques allows malware to bypass multiple mitigations like UAC, access control lists, heuristics detection techniques and allowing malware to remain stealthier while moving laterally inside the network.

 

Access Token Theft and Manipulation Attacks – Technical Analysis

Access Token Theft and Manipulation Attacks – A Door to Local Privilege Escalation.

Read Now

 

The post Access Token Theft and Manipulation Attacks – A Door to Local Privilege Escalation appeared first on McAfee Blogs.

Clever Billing Fraud Applications on Google Play: Etinu

19 April 2021 at 21:42
Saibāsekyuriti

A new wave of fraudulent apps has made its way to the Google Play store, targeting Android users in Southwest Asia and the Arabian Peninsula as well—to the tune of more than 700,000 downloads before detection by McAfee Mobile Research and co-operation with Google to remove the apps.

Figure 1. Infected Apps on Google Play

Posing as photo editors, wallpapers, puzzles, keyboard skins, and other camera-related apps, the malware embedded in these fraudulent apps hijack SMS message notifications and then make unauthorized purchases. While apps go through a review process to ensure that they are legitimate, these fraudulent apps made their way into the store by submitting a clean version of the app for review and then introducing the malicious code via updates to the app later.

Figure 2. Negative reviews on Google Play

McAfee Mobile Security detects this threat as Android/Etinu and alerts mobile users if they are present. The McAfee Mobile Research team continues to monitor this threat and is likewise continuing its co-operation with Google to remove these and other malicious applications on Google Play.

Technical analysis

In terms of details, the malware embedded in these apps takes advantage of dynamic code loading. Encrypted payloads of malware appear in the assets folder associated with the app, using names such as “cache.bin,” “settings.bin,” “data.droid,” or seemingly innocuous “.png” files, as illustrated below.

Figure 3. Encrypted resource sneaked into the assets folder

Figure 4. Decryption flow

The figure above shows the decryption flow. Firstly, the hidden malicious code in the main .apk opens “1.png” file in the assets folder, decrypts it to “loader.dex,” and then loads the dropped .dex. The “1.png” is encrypted using RC4 with the package name as the key. The first payload creates HTTP POST request to the C2 server.

Interestingly, this malware uses key management servers. It requests keys from the servers for the AES encrypted second payload, “2.png”. And the server returns the key as the “s” value of JSON. Also, this malware has self-update function. When the server responds “URL” value, the content in the URL is used instead of “2.png”. However, servers do not always respond to the request or return the secret key.

Figure 5. Updated payload response

As always, the most malicious functions reveal themselves in the final stage. The malware hijacks the Notification Listener to steal incoming SMS messages like Android Joker malware does, without the SMS read permission. Like a chain system, the malware then passes the notification object to the final stage. When the notification has arisen from the default SMS package, the message is finally sent out using WebView JavaScript Interface.

Figure 6. Notification delivery flow

As a result of our additional investigation on C2 servers, following information was found, including carrier, phone number, SMS message, IP address, country, network status, and so forth—along with auto-renewing subscriptions:

Figure 7. Leaked data

Further threats like these to come?

We expect that threats which take advantage of Notification Listener will continue to flourish. The McAfee Mobile Research team continues to monitor these threats and protect customers by analyzing potential malware and working with app stores to remove it. Further, using McAfee Mobile Security can detect such threats and protect you from them via its regular updates. However, it’s important to pay attention to apps that request SMS-related permissions and Notification Listener permissions. Simply put, legitimate photo and wallpaper apps simply won’t ask for those because they’re not necessary for such apps to run. If a request seems suspicious, don’t allow it.

Technical Data and IOCs

MITRE ATT&CK Matrix

IoCs

08C4F705D5A7C9DC7C05EDEE3FCAD12F345A6EE6832D54B758E57394292BA651 com.studio.keypaper2021
CC2DEFEF5A14F9B4B9F27CC9F5BBB0D2FC8A729A2F4EBA20010E81A362D5560C com.pip.editor.camera
007587C4A84D18592BF4EF7AD828D5AAA7D50CADBBF8B0892590DB48CCA7487E org.my.favorites.up.keypaper
08FA33BC138FE4835C15E45D1C1D5A81094E156EEF28D02EA8910D5F8E44D4B8 com.super.color.hairdryer
9E688A36F02DD1B1A9AE4A5C94C1335B14D1B0B1C8901EC8C986B4390E95E760 com.ce1ab3.app.photo.editor
018B705E8577F065AC6F0EDE5A8A1622820B6AEAC77D0284852CEAECF8D8460C com.hit.camera.pip
0E2ACCFA47B782B062CC324704C1F999796F5045D9753423CF7238FE4CABBFA8 com.daynight.keyboard.wallpaper
50D498755486D3739BE5D2292A51C7C3D0ADA6D1A37C89B669A601A324794B06 com.super.star.ringtones

URLs

d37i64jgpubcy4.cloudfront.net

d1ag96m0hzoks5.cloudfront.net

dospxvsfnk8s8.cloudfront.net

d45wejayb5ly8.cloudfront.net

d3u41fvcv6mjph.cloudfront.net

d3puvb2n8wcn2r.cloudfront.net

d8fkjd2z9mouq.cloudfront.net

d22g8hm4svq46j.cloudfront.net

d3i3wvt6f8lwyr.cloudfront.net

d1w5drh895wnkz.cloudfront.net

The post Clever Billing Fraud Applications on Google Play: Etinu appeared first on McAfee Blogs.

McAfee Labs Report Reveals Latest COVID-19 Threats and Malware Surges

13 April 2021 at 04:01

The McAfee Advanced Threat Research team today published the McAfee Labs Threats Report: April 2021.

In this edition, we present new findings in our traditional threat statistical categories – as well as our usual malware, sectors, and vectors – imparted in a new, enhanced digital presentation that’s more easily consumed and interpreted.

Historically, our reports detailed the volume of key threats, such as “what is in the malware zoo.” The introduction of MVISION Insights in 2020 has since made it possible to track the prevalence of campaigns, as well as, their associated IoCs, and determine the in-field detections. This latest report incorporates not only the malware zoo but new analysis for what is being detected in the wild.

The Q3 and Q4 2020 findings include:

  • COVID-19-themed cyber-attack detections increased 114%
  • New malware samples averaging 648 new threats per minute
  • 1 million external attacks observed against MVISION Cloud user accounts
  • Powershell threats spiked 208%
  • Mobile malware surged 118%

Additional Q3 and Q4 2020 content includes:

  • Leading MITRE ATT&CK techniques
  • Prominent exploit vulnerabilities
  • McAfee research of the prolific SUNBURST/SolarWinds campaign

These new, insightful additions really make for a bumper report! We hope you find this new McAfee Labs threat report presentation and data valuable.

Don’t forget keep track of the latest campaigns and continuing threat coverage by visiting our McAfee COVID-19 Threats Dashboard and the MVISION Insights preview dashboard.

The post McAfee Labs Report Reveals Latest COVID-19 Threats and Malware Surges appeared first on McAfee Blogs.

BRATA Keeps Sneaking into Google Play, Now Targeting USA and Spain

12 April 2021 at 16:13
How to check for viruses

Recently, the McAfee Mobile Research Team uncovered several new variants of the Android malware family BRATA being distributed in Google Play, ironically posing as app security scanners.

These malicious apps urge users to update Chrome, WhatsApp, or a PDF reader, yet instead of updating the app in question, they take full control of the device by abusing accessibility services. Recent versions of BRATA were also seen serving phishing webpages targeting users of financial entities, not only in Brazil but also in Spain and the USA.

In this blog post we will provide an overview of this threat, how does this malware operates and its main upgrades compared with earlier versions. If you want to learn more about the technical details of this threat and the differences between all variants you can check the BRATA whitepaper here.

The origins of BRATA

First seen in the wild at the end of 2018 and named “Brazilian Remote Access Tool Android ” (BRATA) by Kaspersky, this “RAT” initially targeted users in Brazil and then rapidly evolved into a banking trojan. It combines full device control capabilities with the ability to display phishing webpages that steal banking credentials in addition to abilities that allow it capture screen lock credentials (PIN, Password or Pattern), capture keystrokes (keylogger functionality), and record the screen of the infected device to monitor a user’s actions without their consent.

Because BRATA is distributed mainly on Google Play, it allows bad actors to lure victims into installing these malicious apps pretending that there is a security issue on the victim’s device and asking to install a malicious app to fix the problem. Given this common ruse, it is recommended to avoid clicking on links from untrusted sources that pretend to be a security software which scans and updates your system—e even if that link leads to an app in Google Play. McAfee offers protection against this threat via McAfee Mobile Security, which detects this malware as Android/Brata.

How BRATA Android malware has evolved and targets new victims

The main upgrades and changes that we have identified in the latest versions of BRATA recently found in Google Play include:

  • Geographical expansion: Initially targeting Brazil, we found that recent variants started to also target users in Spain and the USA.
  • Banking trojan functionality: In addition to being able to have full control of the infected device by abusing accessibility services, BRATA is now serving phishing URLs based on the presence of certain financial and banking apps defined by the remote command and control server.
  • Self-defense techniques: New BRATA variants added new protection layers like string obfuscation, encryption of configuration files, use of commercial packers, and the move of its core functionality to a remote server so it can be easily updated without changing the main application. Some BRATA variants also check first if the device is worth being attacked before downloading and executing their main payload, making it more evasive to automated analysis systems.

BRATA in Google Play

During 2020, the threat actors behind BRATA have managed to publish several apps in Google Play, most of them reaching between one thousand to five thousand installs. However, also a few variants have reached 10,000 installs including the latest one, DefenseScreen, reported to Google by McAfee in October and later removed from Google Play.

Figure 1. DefenseScreen app in Google Play.

From all BRATA apps that were in Google Play in 2020, five of them caught our attention as they have notable improvements compared with previous ones. We refer to them by the name of the developer accounts:

Figure 2. Timeline of identified apps in Google Play from May to October 2020

Social engineering tricks

BRATA poses as a security app scanner that pretends to scan all the installed apps, while in the background it checks if any of the target apps provided by a remote server are installed in the user’s device. If that is the case, it will urge the user to install a fake update of a specific app selected depending on the device language. In the case of English-language apps, BRATA suggests the update of Chrome while also constantly showing a notification at the top of the screen asking the user to activate accessibility services:

Figure 3. Fake app scanning functionality

Once the user clicks on “UPDATE NOW!”, BRATA proceeds to open the main Accessibility tab in Android settings and asks the user to manually find the malicious service and grant permissions to use accessibility services. When the user attempts to do this dangerous action, Android warns of the potential risks of granting access to accessibility services to a specific app, including that the app can observe your actions, retrieve content from Windows, and perform gestures like tap, swipe, and pinch.

As soon as the user clicks on OK the persistent notification goes away, the main icon of the app is hidden and a full black screen with the word “Updating” appears, which could be used to hide automated actions that now can be performed with the abuse of accessibility services:

Figure 4. BRATA asking access to accessibility services and showing a black screen to potentially hide automated actions

At this point, the app is completely hidden from the user, running in the background in constant communication with a command and control server run by the threat actors. The only user interface that we saw when we analyzed BRATA after the access to accessibility services was granted was the following screen, created by the malware to steal the device PIN and use it to unlock it when the phone is unattended. The screen asks the user to confirm the PIN, validating it with the real one because when an incorrect PIN is entered, an error message is shown and the screen will not disappear until the correct PIN is entered:

Figure 5. BRATA attempting to steal device PIN and confirming if the correct one is provided

BRATA capabilities

Once the malicious app is executed and accessibility permissions have been granted, BRATA can perform almost any action in the compromised device. Here’s the list of commands that we found in all the payloads that we have analyzed so far:

  • Steal lock screen (PIN/Password/Pattern)
  • Screen Capture: Records the device’s screen and sends screenshots to the remote server
  • Execute Action: Interact with user’s interface by abusing accessibility services
  • Unlock Device: Use stolen PIN/Password/Pattern to unlock the device
  • Start/Schedule activity lunch: Opens a specific activity provided by the remote server
  • Start/Stop Keylogger: Captures user’s input on editable fields and leaks that to a remote server
  • UI text injection: Injects a string provided by the remote server in an editable field
  • Hide/Unhide Incoming Calls: Sets the ring volume to 0 and creates a full black screen to hide an incoming call
  • Clipboard manipulation: Injects a string provided by the remote server in the clipboard

In addition to the commands above, BRATA also performs automated actions by abusing accessibility services to hide itself from the user or automatically grant privileges to itself:

  • Hides the media projection warning message that explicitly warns the user that the app will start capturing everything displayed on the screen.
  • Grants itself any permissions by clicking on the “Allow” button when the permission dialog appears in the screen.
  • Disables Google Play Store and therefore Google Play Protect.
  • Uninstalls itself in case that the Settings interface of itself with the buttons “Uninstall” and “Force Stop” appears in the screen.

Geographical expansion and Banking Trojan Functionality

Earlier BRATA versions like OutProtect and PrivacyTitan were designed to target Brazilian users only by limiting its execution to devices set to the Portuguese language in Brazil. However, in June we noticed that threat actors behind BRATA started to add support to other languages like Spanish and English. Depending on the language configured in the device, the malware suggested that one of the following three apps needed an urgent update: WhatsApp (Spanish), a non-existent PDF Reader (Portuguese) and Chrome (English):

Figure 6. Apps falsely asked to be updated depending on the device language

In addition to the localization of the user-interface strings, we also noticed that threat actors have updated the list of targeted financial apps to add some from Spain and USA. In September, the target list had around 52 apps but only 32 had phishing URLs. Also, from the 20 US banking apps present in the last target list only 5 had phishing URLs. Here’s an example of phishing websites that will be displayed to the user if specific US banking apps are present in the compromised device:

Figure 7. Examples of phishing websites pretending to be from US banks

Multiple Obfuscation Layers and Stages

Throughout 2020, BRATA constantly evolved, adding different obfuscation layers to impede its analysis and detection. One of the first major changes was moving its core functionality to a remote server so it can be easily updated without changing the original malicious application. The same server is used as a first point of contact to register the infected device, provide an updated list of targeted financial apps, and then deliver the IP address and port of the server that will be used by the attackers to execute commands remotely on the compromised device:

 

Figure 8. BRATA high level network communication

Additional protection layers include string obfuscation, country and language check, encryption of certain key strings in assets folder, and, in latest variants, the use of a commercial packer that further prevents the static and dynamic analysis of the malicious apps. The illustration below provides a summary of the different protection layers and execution stages present in the latest BRATA variants:

Figure 9. BRATA protection layers and execution stages

Prevention and defense

In order get infected with BRATA ,users must install the malicious application from Google Play so below are some recommendations to avoid being tricked by this or any other Android threats that use social engineering to convince users to install malware that looks legitimate:

  • Don’t trust an Android application just because it’s available in the official store. In this case, victims are mainly lured to install an app that promises a more secure device by offering a fake update. Keep in mind that in Android updates are installed automatically via Google Play so users shouldn’t require the installation of a third-party app to have the device up to date.
  • McAfee Mobile Security will alert users if they are attempting to install or execute a malware even if it’s downloaded from Google Play. We recommend users to have a reliable and updated antivirus installed on their mobile devices to detect this and other malicious applications.
  • Do not click on suspicious links received from text messages or social media, particularly from unknown sources. Always double check by other means if a contact that sends a link without context was really sent by that person, because it could lead to the download of a malicious application.
  • Before installing an app, check the developer information, requested permissions, the number of installations, and the content of the reviews. Sometimes applications could have very good rating but most of the reviews could be fake, such as we uncovered in Android/LeifAccess. Be aware that ranking manipulation happens and that reviews are not always trustworthy.

The activation of accessibility services is very sensitive in Android and key to the successful execution of this banking trojan because, once the access to those services is granted, BRATA can perform all the malicious activities and take control of the device. For this reason, Android users must be very careful when granting this access to any app.

Accessibility services are so powerful that in hands of a malicious app they could be used to fully compromise your device data, your online banking and finances, and your digital life overall.

BRATA Android malware continues to evolve—another good reason for protecting mobile devices

When BRATA was initially discovered in 2019 and named “Brazilian Android RAT” by Kaspersky, it was said that, theoretically, the malware can be used to target other users if the cybercriminals behind this threat wanted to do it. Based on the newest variants found in 2020, the theory has become reality, showing that this threat is currently very active, constantly adding new targets, new languages and new protection layers to make its detection and analysis more difficult.

In terms of functionality, BRATA is just another example of how powerful the (ab)use of accessibility services is and how, with just a little bit of social engineering and persistence, cybercriminals can trick users into granting this access to a malicious app and basically getting total control of the infected device. By stealing the PIN, Password or Pattern, combined with the ability to record the screen, click on any button and intercept anything that is entered in an editable field, malware authors can virtually get any data they want, including banking credentials via phishing web pages or even directly from the apps themselves, while also hiding all these actions from the user.

Judging by our findings, the number of apps found in Google Play in 2020 and the increasing number of targeted financial apps, it looks like BRATA will continue to evolve, adding new functionality, new targets, and new obfuscation techniques to target as many users as possible, while also attempting to reduce the risk of being detected and removed from the Play store.

McAfee Mobile Security detects this threat as Android/Brata. To protect yourselves from this and similar threats, employ security software on your mobile devices and think twice before granting access to accessibility services to suspicious apps, even if they are downloaded from trusted sources like Google Play.

Appendix

Techniques, Tactics and Procedures (TTPS)

Figure 10. MITRE ATT&CK Mobile for BRATA

<h3>Indicators of compromise

Apps:

SHA256 Package Name Installs
4cdbd105ab8117620731630f8f89eb2e6110dbf6341df43712a0ec9837c5a9be com.outprotect.android 1,000+
d9bc87ab45b0c786aa09f964a8101f6df7ea76895e2e8438c13935a356d9116b com.privacytitan.android 1,000+
f9dc40a7dd2a875344721834e7d80bf7dbfa1bf08f29b7209deb0decad77e992 com.greatvault.mobile 10,000+
e00240f62ec68488ef9dfde705258b025c613a41760138b5d9bdb2fb59db4d5e com.pw.secureshield 5,000+
2846c9dda06a052049d89b1586cff21f44d1d28f153a2ff4726051ac27ca3ba7 com.defensescreen.application 10,000+

 

URLs:

  • bialub[.]com
  • brorne[.]com
  • jachof[.]com

 

Technical Analysis of BRATA Apps

This paper will analyze five different “Brazilian Remote Access Tool Android” (BRATA) apps found in Google Play during 2020.

View Now

The post BRATA Keeps Sneaking into Google Play, Now Targeting USA and Spain appeared first on McAfee Blogs.

McAfee Defender’s Blog: Cuba Ransomware Campaign

6 April 2021 at 17:00

Cuba Ransomware Overview

Over the past year, we have seen ransomware attackers change the way they have responded to organizations that have either chosen to not pay the ransom or have recovered their data via some other means. At the end of the day, fighting ransomware has resulted in the bad actors’ loss of revenue. Being the creative bunch they are, they have resorted to data dissemination if the ransom is not paid. This means that significant exposure could still exist for your organization, even if you were able to recover from the attack.

Cuba ransomware, no newcomer to the game, has recently introduced this behavior.

This blog is focused on how to build an adaptable security architecture to increase your resilience against these types of attacks and specifically, how McAfee’s portfolio delivers the capability to prevent, detect and respond against the tactics and techniques used in the Cuba Ransomware Campaign.

Gathering Intelligence on Cuba Ransomware

As always, building adaptable defensive architecture starts with intelligence. In most organizations, the Security Operations team is responsible for threat intelligence analysis, as well as threat and incident response. McAfee Insights (https://www.mcafee.com/enterprise/en-us/lp/insights-dashboard1.html#) is a great tool for the threat intel analyst and threat responder. The Insights Dashboard identifies prevalence and severity of emerging threats across the globe which enables the Security Operations Center (SOC) to prioritize threat response actions and gather relevant cyber threat intelligence (CTI) associated with the threat, in this case the Cuba ransomware campaign. The CTI is provided in the form of technical indicators of compromise (IOCs) as well as MITRE ATT&CK framework tactics and techniques. As a threat intel analyst or responder you can drill down to gather more specific information on Cuba ransomware, such as prevalence and links to other sources of information. You can further drill down to gather more specific actionable intelligence such as indicators of compromise and tactics/techniques aligned to the MITRE ATT&CK framework.

From the McAfee Advanced Threat Research (ATR) blog, you can see that Cuba ransomware leverages tactics and techniques common to other APT campaigns. Currently, the Initial Access vector is not known. It could very well be spear phishing, exploited system tools and signed binaries, or a multitude of other popular methods.

Defensive Architecture Overview

Today’s digital enterprise is a hybrid environment of on-premise systems and cloud services with multiple entry points for attacks like Cuba ransomware. The work from home operating model forced by COVID-19 has only expanded the attack surface and increased risk for successful spear phishing attacks if organizations did not adapt their security posture and increase training for remote workers. Mitigating the risk of attacks like Cuba ransomware requires a security architecture with the right controls at the device, on the network and in security operations (SecOps). The Center for Internet Security (CIS) Top 20 Cyber Security Controls provides a good guide to build that architecture. As indicated earlier, the exact entry vector used by Cuba ransomware is currently unknown, so what follows, here, are more generalized recommendations for protecting your enterprise.

Initial Access Stage Defensive Overview

According to Threat Intelligence and Research, the initial access for Cuba ransomware is not currently known. As attackers can leverage many popular techniques for initial access, it is best to validate efficacy on all layers of defenses. This includes user awareness training and response procedures, intelligence and behavior-based malware defenses on email systems, web proxy and endpoint systems, and finally SecOps playbooks for early detection and response against suspicious email attachments or other phishing techniques. The following chart summarizes the controls expected to have the most effect against initial stage techniques and the McAfee solutions to implement those controls where applicable.

MITRE Tactic MITRE Techniques CSC Controls McAfee Capability
Initial Access Spear Phishing Attachments (T1566.001) CSC 7 – Email and Web Browser Protection

CSC 8 – Malware Defenses

CSC 17 – User Awareness

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection,

Web Gateway (MWG), Advanced Threat Defense, Web Gateway Cloud Service (WGCS)

Initial Access Spear Phishing Link (T1566.002) CSC 7 – Email and Web Browser Protection

CSC 8 – Malware Defenses

CSC 17 – User Awareness

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection,

Web Gateway (MWG), Advanced Threat Defense, Web Gateway Cloud Service (WGCS)

Initial Access Spear Phishing (T1566.003) Service CSC 7 – Email and Web Browser Protection

CSC 8 – Malware Defenses

CSC 17 – User Awareness

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection,

Web Gateway (MWG), Advanced Threat Defense, Web Gateway Cloud Service (WGCS)

For additional information on how McAfee can protect against suspicious email attachments, review this additional blog post: https://www.mcafee.com/blogs/other-blogs/mcafee-labs/mcafee-protects-against-suspicious-email-attachments/

Exploitation Stage Defensive Overview

The exploitation stage is where the attacker gains access to the target system. Protection against Cuba ransomware at this stage is heavily dependent on adaptable anti-malware on both end user devices and servers, restriction of application execution, and security operations tools like endpoint detection and response sensors.

McAfee Endpoint Security 10.7 provides a defense in depth capability, including signatures and threat intelligence, to cover known bad indicators or programs, as well as machine-learning and behavior-based protection to reduce the attack surface against Cuba ransomware and detect new exploitation attack techniques. If the initial entry vector is a weaponized Word document with links to external template files on a remote server, for example, McAfee Threat Prevention and Adaptive Threat Protection modules protect against these techniques.

The following chart summarizes the critical security controls expected to have the most effect against exploitation stage techniques and the McAfee solutions to implement those controls where applicable.

MITRE Tactic MITRE Techniques CSC Controls McAfee Portfolio Mitigation
Execution User Execution (T1204) CSC 5 Secure Configuration

CSC 8 Malware Defenses

CSC 17 Security Awareness

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection, Application Control (MAC), Web Gateway and Network Security Platform
Execution Command and Scripting Interpreter (T1059)

 

CSC 5 Secure Configuration

CSC 8 Malware Defenses

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection, Application Control (MAC), MVISION EDR
Execution Shared Modules (T1129) CSC 5 Secure Configuration

CSC 8 Malware Defenses

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection, Application Control (MAC)
Persistence Boot or Autologon Execution (T1547) CSC 5 Secure Configuration

CSC 8 Malware Defenses

Endpoint Security Platform 10.7 Threat Prevention, MVISION EDR
Defensive Evasion Template Injection (T1221) CSC 5 Secure Configuration

CSC 8 Malware Defenses

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection, MVISION EDR
Defensive Evasion Signed Binary Proxy Execution (T1218) CSC 4 Control Admin Privileges

CSC 5 Secure Configuration

CSC 8 Malware Defenses

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection, Application Control, MVISION EDR
Defensive Evasion Deobfuscate/Decode Files or Information (T1027)

 

CSC 5 Secure Configuration

CSC 8 Malware Defenses

Endpoint Security Platform 10.7, Threat Prevention, Adaptive Threat Protection, MVISION EDR

For more information on how McAfee Endpoint Security 10.7 can prevent some of the techniques used in the Cuba ransomware exploit stage, review this additional blog post: https://www.mcafee.com/blogs/other-blogs/mcafee-labs/mcafee-amsi-integration-protects-against-malicious-scripts/

Impact Stage Defensive Overview

The impact stage is where the attacker encrypts the target system, data and perhaps moves laterally to other systems on the network. Protection at this stage is heavily dependent on adaptable anti-malware on both end user devices and servers, network controls and security operation’s capability to monitor logs for anomalies in privileged access or network traffic. The following chart summarizes the controls expected to have the most effect against impact stage techniques and the McAfee solutions to implement those controls where applicable:

The public leak site of Cuba ransomware can be found via TOR: http://cuba4mp6ximo2zlo[.]onion/

MITRE Tactic MITRE Techniques CSC Controls McAfee Portfolio Mitigation
Discovery Account Discovery (T1087) CSC 4 Control Use of Admin Privileges

CSC 5 Secure Configuration

CSC 6 Log Analysis

MVISION EDR, MVISION Cloud, Cloud Workload Protection
Discovery System Information Discovery (T1082) CSC 4 Control Use of Admin Privileges

CSC 5 Secure Configuration

CSC 6 Log Analysis

MVISION EDR, MVISION Cloud, Cloud Workload Protection
Discovery System Owner/User Discovery (T1033) CSC 4 Control Use of Admin Privileges

CSC 5 Secure Configuration

CSC 6 Log Analysis

MVISION EDR, MVISION Cloud, Cloud Workload Protection
Command and Control Encrypted Channel (T1573) CSC 8 Malware Defenses

CSC 12 Boundary Defenses

Web Gateway, Network Security Platform

 

Hunting for Cuba Ransomware Indicators

As a threat intel analyst or hunter, you might want to quickly scan your systems for any indicators you received on Cuba ransomware. Of course, you can do that manually by downloading a list of indicators and searching with available tools. However, if you have MVISION EDR and Insights, you can do that right from the console, saving precious time. Hunting the attacker can be a game of inches so every second counts. Of course, if you found infected systems or systems with indicators, you can take action to contain and start an investigation for incident response immediately from the MVISION EDR console.

In addition to these IOCs, YARA rules are available in our technical analysis of Cuba ransomware.

IOCs:

Files:

151.bat

151.ps1

Kurva.ps1

 

Email addresses:

[email protected][.]ch

[email protected][.]li

[email protected][.]com

[email protected][.]ch

[email protected]

[email protected]

[email protected]

 

Domain:

kurvalarva[.]com

 

Script for lateral movement and deployment:

54627975c0befee0075d6da1a53af9403f047d9e367389e48ae0d25c2a7154bc

c385ef710cbdd8ba7759e084051f5742b6fa8a6b65340a9795f48d0a425fec61

40101fb3629cdb7d53c3af19dea2b6245a8d8aa9f28febd052bb9d792cfbefa6

 

Cuba Ransomware:

c4b1f4e1ac9a28cc9e50195b29dde8bd54527abc7f4d16899f9f8315c852afd4

944ee8789cc929d2efda5790669e5266fe80910cabf1050cbb3e57dc62de2040
78ce13d09d828fc8b06cf55f8247bac07379d0c8b8c8b1a6996c29163fa4b659
33352a38454cfc247bc7465bf177f5f97d7fd0bd220103d4422c8ec45b4d3d0e

672fb249e520f4496e72021f887f8bb86fec5604317d8af3f0800d49aa157be1
e942a8bcb3d4a6f6df6a6522e4d5c58d25cdbe369ecda1356a66dacbd3945d30

907f42a79192a016154f11927fbb1e6f661f679d68947bddc714f5acc4aa66eb
28140885cf794ffef27f5673ca64bd680fc0b8a469453d0310aea439f7e04e64
271ef3c1d022829f0b15f2471d05a28d4786abafd0a9e1e742bde3f6b36872ad
6396ea2ef48aa3d3a61fb2e1ca50ac3711c376ec2b67dbaf64eeba49f5dfa9df

bda4bddcbd140e4012bab453e28a4fba86f16ac8983d7db391043eab627e9fa1

7a17f344d916f7f0272b9480336fb05d33147b8be2e71c3261ea30a32d73fecb

c206593d626e1f8b9c5d15b9b5ec16a298890e8bae61a232c2104cbac8d51bdd

9882c2f5a95d7680626470f6c0d3609c7590eb552065f81ab41ffe074ea74e82

c385ef710cbdd8ba7759e084051f5742b6fa8a6b65340a9795f48d0a425fec61
54627975c0befee0075d6da1a53af9403f047d9e367389e48ae0d25c2a7154bc
1f825ef9ff3e0bb80b7076ef19b837e927efea9db123d3b2b8ec15c8510da647
40101fb3629cdb7d53c3af19dea2b6245a8d8aa9f28febd052bb9d792cfbefa6

00ddbe28a31cc91bd7b1989a9bebd43c4b5565aa0a9ed4e0ca2a5cfb290475ed

729950ce621a4bc6579957eabb3d1668498c805738ee5e83b74d5edaf2f4cb9e

 

MITRE ATT&CK Techniques:

Tactic Technique Observable IOCs
Execution Command and Scripting Interpreter: PowerShell (T1059.001) Cuba team is using PowerShell payload to drop Cuba ransomware f739977004981fbe4a54bc68be18ea79

68a99624f98b8cd956108fedcc44e07c

bdeb5acc7b569c783f81499f400b2745

 

Execution System Services: Service Execution (T1569.002)  

 

Execution Shared Modules (T1129) Cuba ransomware links function at runtime Functions:

“GetModuleHandle”

“GetProcAddress”

“GetModuleHandleEx”

Execution Command and Scripting Interpreter (T1059) Cuba ransomware accepts command line arguments Functions:

“GetCommandLine”

Persistence Create or Modify System Process: Windows Service (T1543.003) Cuba ransomware can modify services Functions:

“OpenService”

“ChangeServiceConfig”

Privilege Escalation Access Token Manipulation (T1134) Cuba ransomware can adjust access privileges Functions:

“SeDebugPrivilege”

“AdjustTokenPrivileges”

“LookupPrivilegeValue”

Defense Evasion File and Directory Permissions Modification (T1222) Cuba ransomware will set file attributes Functions:

“SetFileAttributes”

Defense Evasion Obfuscated files or Information (T1027) Cuba ransomware is using xor algorithm to encode data
Defense Evasion Virtualization/Sandbox Evasion: System Checks Cuba ransomware executes anti-vm instructions
Discovery File and Directory Discovery (T1083) Cuba ransomware enumerates files Functions:

“FindFirstFile”

“FindNextFile”

“FindClose”

“FindFirstFileEx”

“FindNextFileEx”

“GetFileSizeEx”

Discovery Process Discovery (T1057) Cuba ransomware enumerates process modules Functions:

“K32EnumProcesses”

Discovery System Information Discovery (T1082) Cuba ransomware can get keyboard layout, enumerates disks, etc Functions:

“GetKeyboardLayoutList”

“FindFirstVolume”

“FindNextVolume”

“GetVolumePathNamesForVolumeName”

“GetDriveType”

“GetLogicalDriveStrings”

“GetDiskFreeSpaceEx”

Discovery System Service Discovery (T1007) Cuba ransomware can query service status Functions:

“QueryServiceStatusEx”

Collection Input Capture: Keylogging (T1056.001) Cuba ransomware logs keystrokes via polling Functions:

“GetKeyState”

“VkKeyScan”

Impact Service Stop (T1489) Cuba ransomware can stop services
Impact Data encrypted for Impact (T1486) Cuba ransomware encrypts data

 

Proactively Detecting Cuba Ransomware Techniques

Many of the exploit stage techniques in this attack could use legitimate Windows processes and applications to either exploit or avoid detection. We discussed, above, how the Endpoint Protection Platform can disrupt weaponized documents but, by using MVISION EDR, you can get more visibility. As security analysts, we want to focus on suspicious techniques used by Initial Access, as this attack’s Initial Access is unknown.

Monitoring or Reporting on Cuba Ransomware Events

Events from McAfee Endpoint Protection and McAfee MVISION EDR play a key role in Cuba ransomware incident and threat response. McAfee ePO centralizes event collection from all managed endpoint systems. As a threat responder, you may want to create a dashboard for Cuba ransomware-related threat events to understand your current exposure.

Summary

To defeat targeted threat campaigns, defenders must collaborate internally and externally to build an adaptive security architecture which will make it harder for threat actors to succeed and build resilience in the business. This blog highlights how to use McAfee’s security solutions to prevent, detect and respond to Cuba ransomware and attackers using similar techniques.

McAfee ATR is actively monitoring this campaign and will continue to update McAfee Insights and its social networking channels with new and current information. Want to stay ahead of the adversaries? Check out McAfee Insights for more information.

The post McAfee Defender’s Blog: Cuba Ransomware Campaign appeared first on McAfee Blogs.

McAfee ATR Threat Report: A Quick Primer on Cuba Ransomware

6 April 2021 at 17:00

Executive Summary 

Cuba ransomware is an older ransomware, that has recently undergone some development. The actors have incorporated the leaking of victim data to increase its impact and revenue, much like we have seen recently with other major ransomware campaigns. 

In our analysis, we observed that the attackers had access to the network before the infection and were able to collect specific information in order to orchestrate the attack and have the greatest impact. The attackers operate using a set of PowerShell scripts that enables them to move laterally. The ransom note mentions that the data was exfiltrated before it was encrypted. In similar attacks we have observed the use of Cobalt Strike payload, although we have not found clear evidence of a relationship with Cuba ransomware. 

We observed Cuba ransomware targeting financial institutions, industry, technology and logistics organizations.  

The following picture shows an overview of the countries that have been impacted according to our telemetry.  

Coverage and Protection Advice 

Defenders should be on the lookout for traces and behaviours that correlate to open source pen test tools such as winPEASLazagne, Bloodhound and Sharp Hound, or hacking frameworks like Cobalt Strike, Metasploit, Empire or Covenant, as well as abnormal behavior of non-malicious tools that have a dual use. These seemingly legitimate tools (e.g., ADfindPSExec, PowerShell, etc.) can be used for things like enumeration and execution. Subsequently, be on the lookout for abnormal usage of Windows Management Instrumentation WMIC (T1047). We advise everyone to check out the following blogs on evidence indicators for a targeted ransomware attack (Part1Part2).  

Looking at other similar Ransomware-as-a-Service families we have seen that certain entry vectors are quite common among ransomware criminals: 

  • E-mail Spear phishing (T1566.001) often used to directly engage and/or gain an initial foothold. The initial phishing email can also be linked to a different malware strain, which acts as a loader and entry point for the attackers to continue completely compromising a victim’s network. We have observed this in the past with the likes of Trickbot & Ryuk or Qakbot & Prolock, etc.  
  • Exploit Public-Facing Application (T1190) is another common entry vector, given cyber criminals are often avid consumers of security news and are always on the lookout for a good exploit. We therefore encourage organizations to be fast and diligent when it comes to applying patches. There are numerous examples in the past where vulnerabilities concerning remote access software, webservers, network edge equipment and firewalls have been used as an entry point.  
  • Using valid accounts (T1078) is and has been a proven method for cybercriminals to gain a foothold. After all, why break the door down if you already have the keys? Weakly protected RDP access is a prime example of this entry method. For the best tips on RDP security, please see our blog explaining RDP security. 
  • Valid accounts can also be obtained via commodity malware such as infostealers that are designed to steal credentials from a victim’s computer. Infostealer logs containing thousands of credentials can be purchased by ransomware criminals to search for VPN and corporate logins. For organizations, having a robust credential management and MFA on user accounts is an absolute must have.  

When it comes to the actual ransomware binary, we strongly advise updating and upgrading endpoint protection, as well as enabling options like tamper protection and Rollback. Please read our blog on how to best configure ENS 10.7 to protect against ransomware for more details. 

For active protection, more details can be found on our website –  https://www.mcafee.com/enterprise/en-us/threat-center/threat-landscape-dashboard/ransomware-details.cuba-ransomware.html – and in our detailed Defender blog. 

Summary of the Threat 

  • Cuba ransomware is currently hitting several companies in north and south America, as well as in Europe.  
  • The attackers use a set of obfuscated PowerShell scripts to move laterally and deploy their attack.  
  • The website to leak the stolen data has been put online recently.  
  • The malware is obfuscated and comes with several evasion techniques.  
  • The actors have sold some of the stolen data 
  • The ransomware uses multiple argument options and has the possibility to discover shared resources using the NetShareEnum API. 

Learn more about Cuba ransomware, Yara Rules, Indicators of Compromise & Mitre ATT&CK techniques used by reading our detailed technical analysis.

The post McAfee ATR Threat Report: A Quick Primer on Cuba Ransomware appeared first on McAfee Blogs.

McAfee Defenders Blog: Reality Check for your Defenses

31 March 2021 at 16:22
How to check for viruses

Welcome to reality

Ever since I started working in IT Security more than 10 years ago, I wondered, what helps defend against malware the best?

This simple question does not stand on its own, as there are several follow-up questions to that:

  1. How is malware defined? Are we focusing solely on Viruses and Trojans, or do we also include Adware and others?
  2. What malware types are currently spread across the globe? What died of old age and what is brand new?
  3. How does malware operate? Is file-less malware a short-lived trend or is it here to stay?
  4. What needs to be done to adequately defend against malware? What capabilities are needed?
  5. What defenses are already in place? Are they configured correctly?

This blog will guide you through my research and thought process around these questions and how you can enable yourself to answer these for your own organization!

A quick glance into the past

As mentioned above, the central question “what helps best?” has followed me throughout the years, but my methods to be able to answer this question have evolved. The first interaction I had with IT Security was more than 10 years ago, where I had to manually deploy new Anti-Virus software from a USB-key to around 100 devices. The settings were configured by a colleague in our IT-Team, and my job was to help remove infections when they came up, usually by going through the various folders or registry keys and cleaning up the remains. The most common malware was Adware, and the good-ol obnoxious hotbars which were added to the browser. I remember one colleague calling into IT saying “my internet has become so small, I can barely even read 5 lines of text” which we later translated into “I had 6 hotbars installed on my Internet Explorer so there was nearly no space left for the content to be displayed”.

Exemplary picture of the “internet” getting smaller.

Jump ahead a couple of years, I started working with McAfee ePolicy Orchestrator to manage and deploy Anti-Malware from a central place automatically, and not just for our own IT, but I was was allowed to implement McAfee ePO into our customers’ environments. This greatly expanded my view into what happens in the world of malware and I started using the central reporting tool to figure out where all these threats were coming from:

 

Also, I was able to understand how the different McAfee tools helped me in detecting and blocking these threats:

But this only showed the viewpoint of one customer and I had to manually overlay them to figure out what defense mechanism worked best. Additionally, I couldn’t see what was missed by the defense mechanisms, either due to configuration, missing signatures, or disabled modules. So, these reports gave me a good viewpoint into the customers I managed, but not the complete picture. I needed a different perspective, perhaps from other customers, other tools, or even other geo-locations.

Let us jump further ahead in my personal IT security timeline to about June 2020:

How a new McAfee solution changed my perception, all while becoming a constant pun

As you could see above, I spent quite a lot of time optimizing setups and configurations to assist customers in increasing their endpoint security. As time progressed, it became clear that solely using Endpoint Protection, especially only based on signatures, was not state of the art. Protection needs to be a combination of security controls rather than the obnoxious silver bullet that is well overplayed in cybersecurity. And still, the best product or solution set doesn’t help if you don’t know what you are looking for (Question 1&2), how to prepare (Question 4) or if you misconfigured the product including all subfolders of “C:\” as an exclusion for On-Access-Scanning (Question 5).

Then McAfee released MVISION Insights this summer and it clicked in my head:

  1. I can never use the word “insights” anymore as everyone would think I use it as a pun
  2. MVISION Insights presented me with verified data of current campaigns running around in the wild
  3. MVISION Insights also aligns the description of threats to the MITRE ATT&CK® Framework, making them comparable
  4. From the ATT&CK™ Framework I could also link from the threat to defensive capabilities

With this data available it was possible to create a heatmap not just by geo-location or a very high number of new threats every day, hour or even minute, but on how specific types of campaigns are operating out in the wild. To start assessing the data, I took 60 ransomware campaigns dating between January and June 2020 and pulled out all the MITRE ATT&CK© techniques that have been used and displayed them on a heatmap:

Amber/Orange: Being used the most, green: only used in 1 or 2 campaigns

Reality Check 1: Does this mapping look accurate?

For me it does, and here is why:

  1. Initial Access comes from either having already access to a system or by sending out spear phishing attachments
  2. Execution uses various techniques from CLI, to PowerShell and WMI
  3. Files and network shares are being discovered so the ransomware knows what to encrypt
  4. Command and control techniques need to be in place to communicate with the ransomware service provider
  5. Files are encrypted on impact, which is kind of a no-brainer, but on the other hand very sound-proof on what we feel what ransomware is doing, and it is underlined by the work of the threat researchers and the resulting data

Next, we need to understand what can be done to detect and ideally block ransomware in its tracks. For this I summarized key malware defense capabilities and mapped them to the tactics being used most:

MITRE Tactic Security Capability Example McAfee solution features
Execution Attack surface reduction ENS Access Protection and Exploit Prevention, MVISION Insights recommendations
Multi-layered detection ENS Exploit Prevention, MVISION Insights telemetry, MVISION EDR Tracing, ATD file analysis
Multi-layered protection ENS On-Access-Scanning using Signatures, GTI, Machine-Learning and more
Rule & Risk-based analytics MVISION EDR tracing
Containment ENS Dynamic Application Containment
Persistence Attack surface reduction ENS Access Protection or Exploit Prevention, MVISION Insights recommendations
Multi-layered detection ENS Exploit Prevention, MVISION Insights telemetry, MVISION EDR Tracing, ATD file analysis
Sandboxing and threat analysis ATD file analysis
Rule & Risk-based analytics MVISION EDR tracing
Containment ENS Dynamic Application Containment
Defense Evasion Attack surface reduction ENS Access Protection and Exploit Prevention, MVISION Insights recommendations
Multi-layered detection ENS Exploit Prevention, MVISION Insights telemetry, MVISION EDR Tracing, ATD file analysis
Sandboxing and threat analysis ATD file analysis
Rule & Risk-based analytics MVISION EDR tracing
Containment ENS Dynamic Application Containment
Discovery Attack surface reduction ENS Access Protection and Exploit Prevention
Multi-layered detection ENS Exploit Prevention, MVISION EDR Tracing, ATD file analysis
Sandboxing and threat analysis ATD file analysis
Rule & Risk-based analytics MVISION EDR tracing
Command & Control Attack surface reduction MVISION Insights recommendations
Multi-layered detection ENS Firewall IP Reputation, MVISION Insights telemetry, MVISION EDR Tracing, ATD file analysis
Multi-layered protection ENS Firewall
Rule & Risk-based analytics MVISION EDR tracing
Containment ENS Firewall and Dynamic Application Containment
Impact Multi-layered detection MVISION EDR tracing, ATD file analysis
Rule & Risk-based analytics MVISION EDR tracing
Containment ENS Dynamic Application Containment
Advanced remediation ENS Advanced Rollback

A description of the McAfee Solutions is provided below. 

Now this allowed me to map the solutions from the McAfee portfolio to each capability, and with that indirectly to the MITRE tactics. But I did not want to end here, as different tools might take a different role in the defensive architecture. For example, MVISION Insights can give you details around your current configuration and automatically overlays it with the current threat campaigns in the wild, giving you the ability to proactively prepare and harden your systems. Another example would be using McAfee Endpoint Security (ENS) to block all unsigned PowerShell scripts, effectively reducing the risk of being hit by a file-less malware based on this technology to nearly 0%. On the other end of the scale, solutions like MVISION EDR will give you great visibility of actions that have occurred, but this happens after the fact, so there is a high chance that you will have some cleaning up to do. This brings me to the topic of “improving protection before moving into detection” but this is for another blog post.

Coming back to the mapping shown above, let us quickly do…

Reality Check 2: Does this mapping feel accurate too?

For me it does, and here is why:

  1. Execution, persistence, and defense evasion are tactics where a lot of capabilities are present, because we have a lot of mature security controls to control what is being executed, in what context and especially defense evasion techniques are good to detect and protect against.
  2. Discovery has no real protection capability mapped to it, as tools might give you indicators that something suspicious is happening but blocking every potential file discovery activity will have a very huge operational impact. However, you can use sandboxing or other techniques to assess what the ransomware is doing and use the result from this analysis to stop ongoing malicious processes.
  3. Impact has a similar story, as you cannot block any process that encrypts a file, as there are many legitimate reasons to do so and hundreds of ways to accomplish this task. But again, you can monitor these actions well and with the right technology in place, even roll back the damage that has been done.

Now with all this data at hand we can come to the final step and bring it all together in one simple graph.

One graph to bind them…

Before we jump into our conclusion, here is a quick summary of the actions I have taken:

  1. Gather data from 60 ransomware campaigns
  2. Pull out the MITRE ATT&CK techniques being used
  3. Map the necessary security capabilities to these techniques
  4. Bucketize the capabilities depending on where they are in the threat defense lifecycle
  5. Map McAfee solutions to the capabilities and applying a weight to the score
  6. Calculate the score for each solution
  7. Create graph for the ransomware detection & protection score for our most common endpoint bundles and design the best fitting security architecture

So, without further ado and with a short drumroll I want to present to you the McAfee security architecture that best defends against current malware campaigns:

For reference, here is a quick breakdown of the components that make up the architecture above:

MVISION ePO is the SaaS-based version of our famous security management solution, which makes it possible to manage a heterogenous set of systems, policies, and events from a central place. Even though I have mentioned the SaaS-based version here, the same is true for our ePO on-premises software as well.

MVISION Insights is a key data source that helps organizations understand what campaigns and threats are trending. This is based on research from our Advanced Threat Research (ATR) team who use our telemetry data inside our Global Threat Intelligence (GTI) big-data platform to enhance the details that are provided.

MVISION Endpoint Detect & Response (EDR) is present in multiple boxes here, as it is a sensor on one side, which sits on the endpoint and collects data, and it is also a cloud service which receives, stores and analyses the data.

EPP is our Endpoint Protection Platform, which contains multiple items working in conjunction. First there is McAfee Endpoint Security (ENS) that is sitting on the device itself and has multiple detection and protection capabilities. For me, the McAfee Threat Intelligence Exchange (TIE) server is always a critical piece to McAfee’s Endpoint Protection Platform and has evolved from a standalone feature to an integrated building block inside ePO and is therefore not shown in the graphic above.

McAfee Advanced Threat Defense (ATD) extends the capabilities of both EPP and EDR, as it can run suspicious files in a separated environment and shares the information gathered with the other components of the McAfee architecture and even 3rd-party tools. It also goes the other way around as ATD allows other security controls to forward files for analysis in our sandbox, but this might be a topic for another blog post.

All the items listed above can be acquired by licensing our MVISION Premium suite in combination with McAfee ATD.

Based on the components and the mapping to the capabilities, I was also able to create a graph based on our most common device security bundles and their respective malware defense score:

In the graph above you can see four of our most sold bundles, ranging from the basic MVISION Standard, up to MVISION Premium in combination with McAfee Advanced Threat Defense (ATD). The line shows the ransomware detection & protection score, steadily rising as you go from left to right. Interestingly, the cost per point, i.e. how much dollar you need to spend to get one point, is much lower when buying the largest option in comparison to the smaller ones. As the absolute cost varies on too many variables, I have omitted an example here. Contact your local sales representative to gather an estimated calculation for your environment.

So, have I come to this conclusion by accident? Let us find out in the last installment of the reality check:

Reality Check 3:  Is this security architecture well suited for today’s threats?

For me it does, and here is why:

  1. It all starts with the technology on the endpoint. A good Endpoint Protection Platform can not only prevent attacks and harden the system, but it can also protect against threats when they are written on a disk or are executed, and then start malicious activities. But what is commonly overlooked: A good endpoint solution can also bring in a lot of visibility, making it the foundation of every good incident response practice.
  2. ATD plays a huge role in the overall architecture as you can see from the increase in points between MVISION Premium and MVISION Premium + ATD in the graph above. It allows the endpoint to have another opinion, which is not limited in time and resources to come to a conclusion, and it has no scan exceptions applied when checking a file. As this is integrated into the protection, it helps block threats before spreading and it certainly provides tremendous details around the malware that was discovered.
  3. MVISION Insights also plays a huge role in both preventative actions, so that you can harden your machines before you are hit, but also in detecting things that might have slipped through the cracks or where new indicators have emerged only after a certain time period.
  4. MVISION EDR has less impact on the scoring, as it is a pure detection technology. However, it also has a similar advantage as our McAfee ATD, as the client only forwards the data, and the heavy lifting is done somewhere else. It also goes back around, as EDR can pull in data from other tools shown above, like ENS, TIE or ATD just to name a few.
  5. MVISION ePO must be present in any McAfee architecture, as it is the heart and soul for every operational task. From managing policies, rollouts, client-tasks, reporting and much more, it plays a critical role and has for more than two decades now.

And the answer is not 42

While writing up my thoughts into the blog post, I was reminded of the “Hitchhikers Guide to the Galaxy”, as my journey in cybersecurity started out with the search for the answer to everything. But over the years it evolved into the multiple questions I prompted at the start of the article:

  1. How is malware defined? Are we focusing solely on Viruses and Trojans, or do we also include Adware and others?
  2. What malware types are currently spread across the globe? What died of old age and what is brand new?
  3. How does malware operate? Is file-less malware a short-lived trend or is it here to stay?
  4. What needs to be done to adequately defend against malware? What capabilities are needed?
  5. What defenses are already in place? Are they configured correctly?

And certainly, the answers to these questions are a moving target. Not only do the tools and techniques by the adversaries evolve, so do all the capabilities on the defensive side.

I welcome you to take the information provided by my research and apply it to your own security architecture:

  • Do you have the right capabilities to protect against the techniques used by current ransomware campaigns?
  • Is detection already a key part of your environment and how does it help to improve your protection?
  • Have you recently tested your defenses against a common threat campaign?
  • Are you sharing detections within your architecture from one security tool to the other?
  • What score would your environment reach?

Thank you for reading this blog post and following my train of thought. I would love to hear back from you, on how you assess yourself, what could be the next focus area for my research or if you want to apply the scoring mechanism on your environment! So please find me on LinkedIn or Twitter, write me a short message or just say “Hi!”.

I also must send out a big “THANK YOU!” to all my colleagues at McAfee helping out during my research: Mo Cashman, Christian Heinrichs, John Fokker, Arnab Roy, James Halls and all the others!

 

The post McAfee Defenders Blog: Reality Check for your Defenses appeared first on McAfee Blogs.

Netop Vision Pro – Distance Learning Software is 20/20 in Hindsight

22 March 2021 at 04:01

The McAfee Labs Advanced Threat Research team is committed to uncovering security issues in both software and hardware to help developers provide safer products for businesses and consumers. We recently investigated software installed on computers used in K-12 school districts. The focus of this blog is on Netop Vision Pro produced by Netop. Our research into this software led to the discovery of four previously unreported critical issues, identified by CVE-2021-27192, CVE-2021-27193, CVE-2021-27194 and CVE-2021-27195. These findings allow for elevation of privileges and ultimately remote code execution, which could be used by a malicious attacker, within the same network, to gain full control over students’ computers. We reported this research to Netop on December 11, 2020 and we were thrilled that Netop was able to deliver an updated version in February of 2021, effectively patching many of the critical vulnerabilities.

Netop Vision Pro is a student monitoring system for teachers to facilitate student learning while using school computers. Netop Vision Pro allows teachers to perform tasks remotely on the students’ computers, such as locking their computers, blocking web access, remotely controlling their desktops, running applications, and sharing documents. Netop Vision Pro is mainly used to manage a classroom or a computer lab in a K-12 environment and is not primarily targeted for eLearning or personal devices. In other words, the Netop Vision Pro Software should never be accessible from the internet in the standard configuration. However, as a result of these abnormal times, computers are being loaned to students to continue distance learning, resulting in schooling software being connected to a wide array of networks increasing the attack surface.

Initial Recon

Netop provides all software as a free trial on its website, which makes it easy for anyone to download and analyze it. Within a few minutes of downloading the software, we were able to have it configured and running without any complications.

We began by setting up the Netop software in a normal configuration and environment. We placed four virtual machines on a local network; three were set up as students and one was set up as a teacher. The three student machines were configured with non-administrator accounts in our attempt to emulate a normal installation. The teacher first creates a “classroom” which then can choose which student PCs should connect. The teacher has full control and gets to choose which “classroom” the student connects to without the student’s input. Once a classroom has been setup, the teacher can start a class which kicks off the session by pinging each student to connect to the classroom. The students have no input if they want to connect or not as it is enforced by the teacher. Once the students have connected to the classroom the teacher can perform a handful of actions to the entire class or individual students.

During this setup we also took note of the permission levels of each component. The student installation needs to be tamperproof and persistent to prevent students from disabling the service. This is achieved by installing the Netop agent as a system service that is automatically started at boot. The teacher install executes as a normal user and does not start at boot. This difference in execution context and start up behavior led us to target the student installs, as an attacker would have a higher chance of gaining elevated system permissions if it was compromised. Additionally, the ratio of students to teachers in a normal school environment would ensure any vulnerabilities found on the student machines would be wider spread.

With the initial install complete, we took a network capture on the local network and took note of the traffic between the teacher and student. An overview of the first few network packets can been seen in Figure 1 below and how the teacher, student transaction begins.

Figure 1: Captured network traffic between teacher and student

Our first observation, now classified as CVE-2021-27194, was that all network traffic was unencrypted with no option to turn encryption on during configuration. We noticed that even information normally considered sensitive, such as Windows credentials (Figure 2) and screenshots (Figure 4), were all sent in plaintext. Windows credentials were observed on the network when a teacher would issue a “Log on” command to the student. This could be used by the teacher or admin to install software or simply help a student log in.

Figure 2: Windows credentials passed in plaintext

Additionally, we observed interesting default behavior where a student connecting to a classroom immediately began to send screen captures to the classroom’s teacher. This allows the teacher to monitor all the students in real time, as shown in Figure 3.

Figure 3: Teacher viewing all student machines via screenshots

Since there is no encryption, these images were sent in the clear. Anyone on the local network could eavesdrop on these images and view the contents of the students’ screens remotely. A new screenshot was sent every few seconds, providing the teacher and any eavesdroppers a near-real time stream of each student’s computer. To capture and view these images, all we had to do was set our network card to promiscuous mode (https://www.computertechreviews.com/definition/promiscuous-mode/) and use a tool like Driftnet (https://github.com/deiv/driftnet). These two steps allowed us to capture the images passed over the network and view every student screen while they were connected to a classroom. The image in Figure 4 is showing a screenshot captured from Driftnet. This led us to file our first vulnerability disclosed as CVE-2021-27194, referencing “CWE-319: Cleartext Transmission of Sensitive Information” for this finding. As pointed out earlier, the teacher and the student clients will communicate directly over the local network. The only way an eavesdropper could access the unencrypted data would be by sniffing the traffic on the same local network as the students.

Figure 4: Image of student’s desktop captured from Driftnet over the network

Fuzzing the Broadcast Messages

With the goal of remote code execution on the students’ computers, we began to dissect the first network packet, which the teacher sends to the students, telling them to connect to the classroom. This was a UDP message sent from the teacher to all the students and can be seen in Figure 5.

Figure 5: Wireshark capture of teacher’s UDP message

The purpose of this packet is to let the student client software know where to find the teacher computer on the network. Because this UDP message is sent to all students in a broadcast style and requires no handshake or setup like TCP, this was a good place to start poking at.

We created a custom Scapy layer (https://scapy.readthedocs.io/en/latest/api/scapy.layers.html) (Figure 6) from the UDP message seen in Figure 5 to begin dissecting each field and crafting our own packets. After a few days of fuzzing with UDP packets, we were able to identify two things. First, we observed a lack of length checks on strings and second, random values sent by the fuzzer were being written directly to the Windows registry. The effect of these tests can easily be seen in Figure 7.

Figure 6: UDP broadcast message from teacher

Even with these malformed entries in the registry (Figure 7) we never observed the application crashing or responding unexpectedly. This means that even though the application wasn’t handling our mutated packet properly, we never overwrote anything of importance or crossed a string buffer boundary.

Figure 7: Un-sanitized characters being written to the Registry

To go further we needed to send the next few packets that we observed from our network capture (Figure 8). After the first UDP message, all subsequent packets were TCP. The TCP messages would negotiate a connection between the student and the teacher and would keep the socket open for the duration of the classroom connection. This TCP negotiation exchange was a transfer of 11 packets, which we will call the handshake.

Figure 8: Wireshark capture of a teacher starting class

Reversing the Network Protocol

To respond appropriately to the TCP connection request, we needed to emulate how a valid teacher would respond to the handshake; otherwise, the student would drop the connection. We began reverse engineering the TCP network traffic and attempted to emulate actual “teacher” traffic. After capturing a handful of packets, the payloads started to conform to roughly the same format. Each started with the size of the packet and the string “T125”. There were three packets in the handshake that contained fields that were changing between each classroom connection. In total, four changing fields were identified.

The first field was the session_id, which we identified in IDA and is shown in the UDP packet from Figure 6. From our fuzzing exercise with the UDP packet, we learned if the same session_id was reused multiple times, the student would still respond normally, even though the actual network traffic we captured would often have a unique session_id.

This left us three remaining dynamic fields which we identified as a teacher token, student token, and a unique unknown DWORD (8 bytes). We identified two of these fields by setting up multiple classrooms with different teacher and student computers and monitoring these values. The teacher token was static and unique to each teacher. We discovered the same was true with the student token. This left us with the unique DWORD field that was dynamic in each handshake. This last field at first seemed random but was always in the same relative range. We labeled this as “Token3” for much of our research, as seen in Figure 9 below.

Figure 9: Python script output identifying “Token3”

Eventually, while using WinDbg to perform dynamic analysis, the value of Token3 started to look familiar. We noticed it matched the range of memory being allocated for the heap. This can be seen in Figure 10.

Figure 10: WinDbg address space analysis from a student PC

By combining our previous understanding of the UDP broadcast traffic with our ability to respond appropriately to the TCP packets with dynamic fields, we were able to successfully emulate a teacher’s workstation. We demonstrated this by modifying our Python script with this new information and sending a request to connect with the student. When a student connects to a teacher it displays a message indicating a successful connection has been made. Below are two images showing a teacher connecting (Figure 11) and our Python script connecting (Figure 12). Purely for demonstration purposes, we have named our attack machine “hacker”, and our classroom “hacker-room.”

Figure 11: Emulation of a teacher successful

Figure 12: Emulated teacher connection from Python script

To understand the process of reverse engineering the network traffic in more detail, McAfee researchers Douglas McKee and Ismael Valenzuela have released an in-depth talk on how to hack proprietary protocols like the one used by Netop. Their webinar goes into far more detail than this blog and can be viewed here.

Replaying a Command Action

Since we have successfully emulated a teacher’s connection using Python, for clarity we will refer to ourselves as the attacker and a legitimate connection made through Netop as the teacher.

Next, we began to look at some of the actions that teachers can perform and how we could take advantage of them. One of the actions that a teacher can perform is starting applications on the remote students’ PCs. In the teacher suite, the teacher is prompted with the familiar Windows Run prompt, and any applications or commands set to run are executed on the student machines (Figure 13).

Figure 13: The teacher “Run Application” prompt

Looking at the network traffic (shown in Figure 14), we were hoping to find a field in the packet that could allow us to deviate from what was possible using the teacher client. As we mentioned earlier, everything is in plaintext, making it quite easy to identify which packets were being sent to execute applications on the remote systems by searching within Wireshark.

Figure 14: Run “calc” packet

Before we started to modify the packet that runs applications on the student machines, we first wanted to see if we could replay this traffic successfully. As you can see in the video below, our Python script was able to run PowerShell followed by Windows Calculator on each of the student endpoints. This is showcasing that even valid teacher actions can still be useful to attackers.

The ability for an attacker to emulate a teacher and execute arbitrary commands on the students’ machines brings us to our second CVE. CVE-2021-27195 was filed for “CWE-863: Incorrect Authorization” since we were able to replay modified local network traffic.

When the teacher sends a command to the student, the client would drop privileges to that of the logged-in student and not keep the original System privileges. This meant that if an attacker wanted unrestricted access to the remote system, they could not simply replay normal traffic, but instead would have to modify each field in the traffic and observe the results.

In an attempt to find a way around the privilege reduction during command execution, we continued fuzzing all fields located within the “run command” packet. This proved unsuccessful as we were unable to find a packet structure that would prevent the command from lowering privileges. This required a deeper dive into the code in handling the remote command execution processed on the student endpoint. By tracing the execution path within IDA, we discovered there was in fact a path that allows remote commands to execute without dropping privileges, but it required a special case, as shown in Figure 15.

Figure 15: IDA graph view showing alternate paths of code execution

Figure 16: Zoomed in image of the ShellExecute code path

The code path that bypasses the privilege reduction and goes directly to “ShellExecute” was checking a variable that had its value set during startup. We were not able to find any other code paths that updated this value after the software started. Our theory is this value may be used during installation or uninstallation, but we were not able to legitimately force execution to the “ShellExecute” path.

This code path to “ShellExecute” made us wonder if there were other similar branches like this that could be reached. We began searching the disassembled code in IDA for calls not wrapped with code resulting in lower privileges. We found four cases where the privileges were not reduced, however none of them were accessible over the network. Regardless, they still could potentially be useful, so we investigated each. The first one was used when opening Internet Explorer (IE) with a prefilled URL. This turned out to be related to the support system. Examining the user interface on the student machine, we discovered a “Technical Support” button which was found in the Netop “about” menu.

When the user clicks on the support button, it opens IE directly into a support web form. The issue, however, is privileges are never dropped, resulting in the IE process being run as System because the Netop student client is also run as System. This can be seen in Figure 11. We filed this issue as our third CVE, CVE-2021-27192 referencing “CWE-269: Incorrect Privilege Assignment”.

Figure 17: Internet Explorer running as System

There are a handful of well-documented ways to get a local elevation of privilege (LPE) using only the mouse when the user has access to an application running with higher privileges. We used an old technique which uses the “Save as” button to navigate to the folder where cmd.exe is located and execute it. The resulting CMD process inherits the System privileges of the parent process, giving the user a System-level shell.

While this LPE was exciting, we still wanted to find something with a remote attack vector and utilize our Python script to emulate teacher traffic. We decided to take a deeper dive into the network traffic to see what we could find. Simulating an attacker, we successfully emulated the following:

  • Remote CMD execution
  • Screen blank the student
  • Restart Netop
  • Shutdown the computer
  • Block web access to individual websites
  • Unlock the Netop properties (on student computer)

During the emulation of all the above actions we performed some rudimentary fuzzing on various fields of each and discovered six crashes which caused the Netop student install to crash and restart. We were able to find two execution violations, two read violations, one write exception, and one kernel exception. After investigation, we determined these crashes were not easily exploitable and therefore a lower priority for deeper investigation. Regardless, we reported them to Netop along with all other findings.

Exploring Plugins

Netop Vision Pro comes with a handful of plugins installed by default, which are used to separate different functionality from the main Netop executable. For example, to enable the ability for the teacher and student to instant message (IM) each other, the MChat.exe plugin is used. With a similar paradigm to the main executable, the students should not be able to stop these plugins, so they too run as System, making them worth exploring.

Mimicking our previous approach, we started to look for “ShellExecute” calls within the plugins and eventually discovered three more privilege escalations, each of which were conducted in a comparable way using only the mouse and bypassing restrictive file filters within the “Save as” windows. The MChat.exe, SSView.exe (Screen Shot Viewer), and the About page’s “System Information” windows all had a similar “Save as” button, each resulting in simple LPEs with no code or exploit required. We added each of these plugins under the affected versions field on our third CVE, CVE-2021-27192, mentioned above.

We were still searching for a method to achieve remote code execution and none of the “ShellExecute” calls used for the LPEs were accessible over the network. We started to narrow down the plugins that pass user supplied data over the network. This directed our attention back to the MChat plugin. As part of our initial recon for research projects, we reviewed change logs looking for any relevant security changes. During this review we noted an interesting log pertaining to the MChat client as seen in Figure 13.

 

Figure 18: Change log from Netop.com

The Chat function runs as System, like all the plugins, and can send text or files to the remote student computer. An attacker can always use this functionality to their advantage by either overwriting existing files or enticing a victim to click on a dropped executable. Investigating how the chat function works and specifically how files are sent, we discovered that the files are pushed to the student computers without any user interaction from the student. Any files pushed by a teacher are stored in a “work directory”, which the student can open from the IM window. Prior to the latest release it would have been opened as System; this was fixed as referenced in Figure 18. Delving deeper into the functionality of the chat application, we found that the teacher also has the ability to read files in the student’s “work directory” and delete files within it. Due to our findings demonstrated with CVE-2021-27195, we can leverage our emulation code as an attacker to write, read, and delete files within this “work directory” from a remote attack vector on the same local network. This ability to read and write files accounted for the last CVE that we filed, CVE-2021-27193 referencing “CWE-276: Incorrect Default Permissions,” with the overall highest CVSS score of 9.5.

In order to determine if the MChat plugin would potentially give us System-level access, we needed to investigate if the plugin’s file operations were restricted to the student’s permissions or if the plugin inherited the System privileges from the running context. Examining the disassembled code of the MChat plugin, as displayed in Figure 14, we learned that all file actions on the student computer are executed with System privileges. Only after the file operation finishes will the permissions be set to allow access for everyone, essentially the effect of using the Linux “chmod 777” command, to make the files universally read/writable.

Figure 19: IDA screenshot of MChat file operations changing access to everyone

To validate this, we created several test files using an admin account and restricted the permissions to disallow the student from modifying or reading the test files. We proceeded to load the teacher suite, and through an MChat session confirmed we were able to read, write, and delete these files. This was an exciting discovery; however, if the attacker is limited to the predetermined “work directory” they would be limited in the effect they could have on the remote target. To investigate if we could change the “work directory” we began digging around in the teacher suite. Hidden in a few layers of menus (Figure 20) we found that a teacher can indeed set the remote student’s “work directory” and update this remotely. Knowing we can easily emulate any teacher’s command means that we could modify the “work directory” anywhere on the student system. Based on this, an attacker leveraging this flaw could have System access to modify any file on the remote PC.

Figure 20: Changing the remote student path from a teacher’s client

Reversing MChat Network Traffic

Now that we knew that the teacher could overwrite any file on the system, including system executables, we wanted to automate this attack and add it to our Python script. By automating this we want to showcase how attackers can use issues like this to create tools and scripts that have real world impacts. For a chat session to begin, we had to initiate the 11-packet handshake we previously discussed. Once the student connected to our attack machine, we needed to send a request to start a chat session with the target student. This request would make the student respond using TCP, yet this time, on a separate port, initiating an MChat seven-packet handshake. This required us to reverse engineer this new handshake format in a similar approach as described earlier. Unlike the first handshake, the MChat handshake had a single unique identifier for each session, and after testing, it was determined that the ID could be hardcoded with a static value without any negative effects.

Finally, we wanted to overwrite a file that we could ensure would be executed with System privileges. With the successful MChat handshake complete we needed to send a packet that would change the “work directory” to that of our choosing. Figure 21 shows the packet as a Scapy layer used to change the work directory on the student’s PC. The Netop plugin directory was a perfect target directory to change to since anything executed from this directory would be executed as System.

Figure 21: Change working directory on the student PC

The last step in gaining System-level execution was to overwrite and execute one of the plugins with a “malicious” binary. Through testing we discovered that if the file already exists in the same directory, the chat application is smart enough to not overwrite it, but instead adds a number to the filename. This is not what we wanted since the original plugin would get executed instead of our “malicious” one. This meant that we had to also reverse engineer a packet containing commands that are used to delete files. The Scapy layer used to delete a file and save a new one is shown in Figure 22.

Figure 22: Python Scapy layers to “delete” (MChatPktDeleteFile)  and “write” (MChatPkt6) files

With these Scapy layers we were able to replace the target plugin with a binary of our choosing, keeping the same name as the original plugin. We chose the “SSView.exe” plugin, which is a plugin used to show screenshots on the student’s computer. To help visualize this entire process please reference Figure 23.

Figure 23: An attack flow using the MChat plugin to overwrite an executable

Now that the SSView.exe plugin has been overwritten, triggering this plugin will execute our attacker-supplied code. This execution will inherit the Netop System privileges, and all can be conducted from an unauthenticated remote attack vector.

Impact

It is not hard to imagine a scenario where a culmination of these issues can lead to several negative outcomes. The largest impact being remote code execution of arbitrary code with System privileges from any device on the local network. This scenario has the potential to be wormable, meaning that the arbitrary binary that we run could be designed to seek out other devices and further the spread. In addition, if the “Open Enrollment” option for a classroom is configured, the Netop Vision Pro student client broadcasts its presence on the network every few seconds. This can be used to an attacker’s advantage to determine the IP addresses of all the students connected on the local network. As seen in Figure 24, our Python script sniffed for student broadcast messages for 5 seconds and found all three student computers on the same network. Because these broadcast messages are sent out to the entire local network, this could very well scale to an entire school system.

Figure 24: Finding all students on the local network.

With a list of computers running the student software, an attacker can then issue commands to each one individually to run arbitrary code with System privileges. In the context of hybrid and e-learning it is important to remember that this software on the student’s computer doesn’t get turned off. Because it is always running, even when not in use, this software assumes every network the device connects to could have a teacher on it and begins broadcasting its presence. An attacker doesn’t have to compromise the school network; all they need is to find any network where this software is accessible, such as a library, coffee shop, or home network. It doesn’t matter where one of these student’s PCs gets compromised as a well-designed malware could lay dormant and scan each network the infected PC connects to, until it finds other vulnerable instances of Netop Vision Pro to further propagate the infection.

Once these machines have been compromised the remote attacker has full control of the system since they inherit the System privileges. Nothing at this point could stop an attacker running as System from accessing any files, terminating any process, or reaping havoc on the compromised machine. To elaborate on the effects of these issues we can propose a few scenarios. An attacker could use the discoverability of these machines to deploy ransomware to all the school computers on the network, bringing the school or entire school district to a standstill. A stealthier attacker could silently install keylogging software and monitor screenshots of the students which could lead to social media or financial accounts being compromised. Lastly, an attacker could monitor webcams of the students, bridging the gap from compromised software to the physical realm. As a proof of concept, the video below will show how an attacker can put CVE-2021-27195 and CVE-2021-27193 together to find, exploit, and monitor the webcams of each computer running Netop Vision Pro.

Secure adaptation of software is much easier to achieve when security is baked in from the beginning, rather than an afterthought. It is easy to recognize when software is built for “safe” environments. While Netop Vision Pro was never intended to be internet-facing or be brought off a managed school network, it is still important to implement basic security features like encryption. While designing software one should not assume what will be commonplace in the future. For instance, when this software was originally developed the concept of remote learning or hybrid learning was a far-out idea but now seems like it will be a norm. When security decisions are integrated from inception, software can adapt to new environments while keeping users better protected from future threats.

Disclosure and Recommended Mitigations

We disclosed all these findings to Netop on December 11, 2020 and heard back from them shortly after. Our disclosure included recommendations for implementing encryption of all network traffic, adding authentication, and verification of teachers to students, and more precise packet parsing filters. In Netop Vision Pro 9.7.2, released in late February, Netop has fixed the local privilege escalations, encrypted formerly plaintext Windows credentials, and mitigated the arbitrary read/writes on the remote filesystem within the MChat client. The local privilege escalations were fixed by running all plugins as the student and no longer as System. This way, the “Save as” buttons are limited to the student’s account. The Windows credentials are now encrypted using RC4 before being sent over the network, preventing eavesdroppers from gathering account credentials. Lastly, since all the plugins are running as the student, the MChat client can no longer delete and replace system executables which successfully mitigates the attack shown in the impact section. The network traffic is still unencrypted, including the screenshots of the student computers but Netop has assured us it is working on implementing encryption on all network traffic for a future update. We’d like to recognize Netop’s outstanding response and rapid development and release of a more secure software version and encourage industry vendors to take note of this as a standard for responding to responsible disclosures from industry researchers.

The post Netop Vision Pro – Distance Learning Software is 20/20 in Hindsight appeared first on McAfee Blogs.

Operation Diànxùn: Cyberespionage Campaign Targeting Telecommunication Companies

16 March 2021 at 13:00
how to run a virus scan

In this report the McAfee Advanced Threat Research (ATR) Strategic Intelligence team details an espionage campaign, targeting telecommunication companies, dubbed Operation Diànxùn.

In this attack, we discovered malware using similar tactics, techniques and procedures (TTPs) to those observed in earlier campaigns publicly attributed to the threat actors RedDelta and Mustang Panda. While the initial vector for the infection is not entirely clear, we believe with a medium level of confidence that victims were lured to a domain under control of the threat actor, from which they were infected with malware which the threat actor leveraged to perform additional discovery and data collection. We believe with a medium level of confidence that the attackers used a phishing website masquerading as the Huawei company career page to target people working in the telecommunications industry.

We discovered malware that masqueraded as Flash applications, often connecting to the domain “hxxp://update.careerhuawei.net” that was under control of the threat actor. The malicious domain was crafted to look like the legitimate career site for Huawei, which has the domain: hxxp://career.huawei.com. In December, we also observed a new domain name used in this campaign: hxxp://update.huaweiyuncdn.com.

Moreover, the sample masquerading as the Flash application used the malicious domain name “flach.cn” which was made to look like the official web page for China to download the Flash application, flash.cn. One of the main differences from past attacks is the lack of use of the PlugX backdoor. However, we did identify the use of a Cobalt Strike backdoor.

 

By using McAfee’s telemetry, possible targets based in Southeast Asia, Europe, and the US were discovered in the telecommunication sector. We also identified a strong interest in GermanVietnamese and India telecommunication companies. Combined with the use of the fake Huawei site, we believe with a high level of confidence that this campaign was targeting the telecommunication sector. We believe with a moderate level of confidence that the motivation behind this specific campaign has to do with the ban of Chinese technology in the global 5G roll-out.

 

Activity linked to the Chinese group RedDelta, by peers in our industry, has been spotted in the wild since early May 2020. Previous attacks have been described targeting the Vatican and religious organizations.

In September 2020, the group continued its activity using decoy documents related to Catholicism, Tibet-Ladakh relations and the United Nations General Assembly Security Council, as well as other network intrusion activities targeting the Myanmar government and two Hong Kong universities. These attacks mainly used the PlugX backdoor using DLL side loading with legitimate software, such as Word or Acrobat, to compromise targets.

While external reports have given a new name to the group which attacked the religious institutions, we believe with a moderate level of confidence, based on the similarity of TTPs, that both attacks can be attributed to one known threat actor: Mustang Panda.

Coverage and Protection

We believe the best way to protect yourself from this type of attack is to adopt a multi-layer approach including MVISION Insights, McAfee Web Gateway, MVISION UCE and MVISION EDR.

MVISION Insights can play a key role in risk mitigation by proactively collecting intelligence on the threat and your exposure.

McAfee Web Gateway and MVISION UCE provide multi-layer web vector protection with URL Reputation check, SSL decryption, and malware emulation capabilities for analyzing dangerous active Web content such as Flash and DotNet. MVISION UCE also includes the capabilities of Remote Browser Isolation, the only solution that can provide 100% protection during web browsing.

McAfee Endpoint Security running on the target endpoint protects against Operation Dianxun with an array of prevention and detection techniques. ENS Threat Prevention and ATP provides both signature and behavioral analysis capability which proactively detects the threat. ENS also leverages Global Threat Intelligence which is updated with known IoCs. For DAT based detections, the family will be reported as Trojan-Cobalt, Trojan-FSYW, Trojan-FSYX, Trojan-FSZC and CobaltStr-FDWE.

As the last phase of the attack involves creating a backdoor for remote control of the victim via a Command and Control Server and Cobalt Strike Beacon, the blocking features that can be activated on a Next Generation Intrusion Prevention System solution such as McAfee NSP are important, NSP includes a Callback Detection engine and is able to detect and block anomalies in communication signals with C2 Servers.

MVISION EDR can proactively identify persistence and defense evasion techniques. You can also use MVISION EDR to search the indicators of compromise in Real-Time or Historically (up to 90 days) across enterprise systems.

Learn more about Operation Diànxùn, including Yara & Mitre ATT&CK techniques, by reading our technical analysis and Defender blog. 

Summary of the Threat

We assess with a high level of confidence that:

  • Recent attacks using TTPs similar to those of the Chinese groups RedDelta and Mustang Panda have been discovered.
  • Multiple overlaps including tooling, network and operating methods suggest strong similarities between Chinese groups RedDelta and Mustang Panda.
  • The targets are mainly telecommunication companies based in Southeast Asia, Europe, and the US. We also identified a strong interest in German and Vietnamese telecommunication companies.

We assess with a moderate level of confidence that:

  • We believe that this espionage campaign is aimed at stealing sensitive or secret information in relation to 5G technology.

PLEASE NOTE:  We have no evidence that the technology company Huawei was knowingly involved in this Campaign.

McAfee Advanced Threat Research (ATR) is actively monitoring this threat and will update as its visibility into the threat increases.

The post Operation Diànxùn: Cyberespionage Campaign Targeting Telecommunication Companies appeared first on McAfee Blogs.

McAfee Defender’s Blog: Operation Dianxun

16 March 2021 at 13:00

Operation Dianxun Overview

In a recent report the McAfee Advanced Threat Research (ATR) Strategic Intelligence team disclosed an espionage campaign, targeting telecommunication companies, named Operation Diànxùn.

The tactics, techniques and procedures (TTPs) used in the attack are like those observed in earlier campaigns publicly attributed to the threat actors RedDelta and Mustang Panda. Most probably this threat is targeting people working in the telecommunications industry and has been used for espionage purposes to access sensitive data and to spy on companies related to 5G technology.

While the initial vector for the infection is not entirely clear, the McAfee ATR team believes with a medium level of confidence that victims were lured to a domain under control of the threat actor, from which they were infected with malware which the threat actor leveraged to perform additional discovery and data collection. It is our belief that the attackers used a phishing website masquerading as the Huawei company career page.

Defensive Architecture Overview

So, how can I defend my organization as effectively as possible from an attack of this type, which involves different techniques and tactics and potential impact? To answer this question, we believe it is necessary to have a multi-layer approach and analyze the various steps, trying to understand the best way to deal with them one by one with an integrated security architecture. Below is a summary of how McAfee’s Security Architecture helps you to protect against the tactics and techniques used in Operation Dianxun.

The goal is to shift-left and block or identify a threat as soon as possible within the Kill Chain to limit any further damage. Shifting-left starts with MVISION Insights, which proactively collects intelligence on the threat and provides details on the indicators of compromise and the MITRE techniques used in the attack. MVISION Insights combines McAfee’s Threat Intelligence research with telemetry from your endpoint controls to reduce your attack surface against emerging threats. MVISION Insights tracks over 800+ Advanced Persistent Threat and Cyber Crime campaigns as researched by McAfee’s ATR team, including Operation Dianxun, sharing a quick summary of the threat, providing external resources, and a list of known indicators such as files, URLs, or IP addresses.

As a threat intelligence analyst or responder, you can drill down into the MVISION Insights interface to gather more specific information on the Operation Dianxun campaign, verify the associated severity, check for geographical prevalence and links to other sources of information. Moreover, MVISION Insights provides useful information like the McAfee products coverage with details of minimum AMCore version; this kind of information is handy to verify actual defensive capabilities within the enterprise and could raise the risk severity in case of weak coverage.

Additional information is available to further investigate on IoCs and MITRE Techniques associated to the campaign. IoCs can be also exported in STIX2 format to be ingested in other tools for automating responses or updating defenses.

The first step ahead of identification is to ensure our architecture can stop or identify the threat in the initial access vector. In this case, the initial delivery vector is a phishing attack so the web channel is therefore fundamental in the initial phase of the infection. McAfee Web Gateway and MVISION UCE provide multi-layer web vector protection with URL Reputation check, SSL decryption, and malware emulation capabilities for analyzing dangerous active Web content.

MVISION UCE also includes the capabilities of Remote Browser Isolation (RBI), the only solution that can provide 100% protection during web browsing. Remote Browser Isolation is indeed an innovative new technology that contains web browsing activity inside an isolated cloud environment in order to protect users from any malware or malicious code that may be hidden on a website. RBI technology provides the most powerful form of web threat protection available, eliminating the opportunity for malicious code to even touch the end user’s device.

The green square around the page means that the web content is isolated by RBI and provided safely through a rendered dynamic visual stream which delivers full browsing experience without risk of infection.

The second phase of exploitation and persistence results from execution on the victim endpoint of Flash-based artifacts malware and, later, DotNet payload. McAfee Endpoint Security running on the target endpoint protects against Operation Dianxun with an array of prevention and detection techniques. ENS Threat Prevention and ATP provides both signature and behavioral analysis capability which proactively detects the threat. ENS also leverages Global Threat Intelligence which is updated with known IoCs. For DAT based detections, the family will be reported as Trojan-Cobalt, Trojan-FSYW, Trojan-FSYX, Trojan-FSZC and CobaltStr-FDWE.

While the execution of the initial fake Flash installer acts mainly like a downloader, the DotNet payload contains several functions and acts as a utility to further compromise the machine. This is a tool to manage and download backdoors to the machine and configure persistence. Thus, the McAfee Endpoint Security Adaptive Threat Protection machine-learning engine triggers detection and blocks execution on its behavior-based analysis.

The last phase of the attack involves creating a backdoor for remote control of the victim via a Command and Control Server and Cobalt Strike Beacon. In this case, in addition to the detection capabilities present at the McAfee Endpoint Security level, detections and blocking features that can be activated on a Next Generation Intrusion Prevention System solution such as McAfee NSP are important. NSP includes a Callback Detection engine and is able to detect and block anomalies in communication signals with C2 Servers.

Investigation and Threat Hunting with MVISION EDR

We demonstrated above how a well defended architecture can thwart and counteract such an attack in each single phase. McAfee Web Gateway and MVISON Unified Cloud Edge can stop the initial entry vector, McAfee Endpoint Protection Platform can block the dropper execution or disrupt the following malicious activities but, only by using MVISION EDR, can you get extensive visibility on the full kill chain.

On MVISION EDR we have the threat detection on the monitoring dashboard for the two different stages and processes of the attack.

Once alerted, the security analyst can dig into the Process Activity and understand behavior and indicators relative to what happened like:

The initial downloader payload flashplayer_install_cn.exe is executed directly by the user and spawned by svchost.exe.

At first it connects back to hxxp://update.flach.cn registering to the c2 and creates a new executable file, flash.exe, in the Windows/temp folder.

Then the sample checks the time and the geolocalization of the infected machine via a request to http://worldclockapi.com.

Next, it connects back to the fake Huawei website “hxxp:\\update.careerhuawei.net” used for the initial phishing attack.

Finally, to further completion, you can also use MVISION EDR to search the indicators of compromise in Real-Time or Historically (up to 90 days) across the enterprise systems.

Looking for other systems with evidence of connection to the fake Huawei website:

HostInfo hostname, ip_address and NetworkFlow src_ip, proto, time, process, md5, user where NetworkFlow dst_ip equals “8.210.186.138”

Looking for indicators of the initial downloader payload linked to this campaign.

HostInfo and Files name, full_name, create_user_name, sha1, md5, sha256 where Files sha256 equals “422e3b16e431daa07bae951eed08429a0c4ccf8e37746c733be512f1a5a160a3” or Files sha256 equals “8489ee84e810b5ed337f8496330e69d6840e7c8e228b245f6e28ac6905c19f4a ” or Files sha256 equals “c0331d4dee56ef0a8bb8e3d31bdfd3381bafc6ee80b85b338cee4001f7fb3d8c” or Files sha256 equals “89a1f947b96b39bfd1fffd8d0d670dddd2c4d96f9fdae96f435f2363a483c0e1” or Files sha256 equals “b3fd750484fca838813e814db7d6491fea36abe889787fb7cf3fb29d9d9f5429” or Files sha256 equals “9ccb4ed133be5c9c554027347ad8b722f0b4c3f14bfd947edfe75a015bf085e5” or Files sha256 equals “4e7fc846be8932a9df07f6c5c9cbbd1721620a85c6363f51fa52d8feac68ff47” or Files sha256 equals “0f2e16690fb2ef2b5b4c58b343314fc32603364a312a6b230ab7b4b963160382” or Files sha256 equals “db36ad77875bbf622d96ae8086f44924c37034dd95e9eb6d6369cc6accd2a40d” or Files sha256 equals “8bd55ecb27b94b10cb9b36ab40c7ea954cf602761202546f9b9e163de1dde8eb” or Files sha256 equals “7de56f65ee98a8cd305faefcac66d918565f596405020178aee47a3bd9abd63c” or Files sha256 equals “9d4b4c39106f8e2fd036e798fc67bbd7b98284121724c0f845bca0a6d2ae3999” or Files sha256 equals “ac88a65345b247ea3d0cfb4d2fb1e97afd88460463a4fc5ac25d3569aea42597” or Files sha256 equals “37643f752302a8a3d6bb6cc31f67b8107e6bbbb0e1a725b7cebed2b79812941f” or Files sha256 equals “d0dd9c624bb2b33de96c29b0ccb5aa5b43ce83a54e2842f1643247811487f8d9” or Files sha256 equals “260ebbf392498d00d767a5c5ba695e1a124057c1c01fff2ae76db7853fe4255b” or Files sha256 equals “e784e95fb5b0188f0c7c82add9a3c89c5bc379eaf356a4d3876d9493a986e343” or Files sha256 equals “a95909413a9a72f69d3c102448d37a17659e46630999b25e7f213ec761db9e81” or Files sha256 equals “b7f36159aec7f3512e00bfa8aa189cbb97f9cc4752a635bc272c7a5ac1710e0b” or Files sha256 equals “4332f0740b3b6c7f9b438ef3caa995a40ce53b3348033b381b4ff11b4cae23bd”

Look back historically for domain name resolution and network connection to the involved indicators.

Summary

To defeat targeted threat campaigns like Operation Dianxun, defenders must build an adaptive and integrated security architecture which will make it harder for threat actors to succeed and increase resilience in the business. This blog highlights how to use McAfee’s security solutions to prevent, detect and respond to Operation Dianxun and attackers using similar techniques.

McAfee ATR is actively monitoring this campaign and will continue to update McAfee Insights and its social networking channels with new and current information. Want to stay ahead of the adversaries? Check out McAfee Insights for more information.

The post McAfee Defender’s Blog: Operation Dianxun appeared first on McAfee Blogs.

Seven Windows Wonders – Critical Vulnerabilities in DNS Dynamic Updates

9 March 2021 at 18:13
how to run a virus scan

Overview

For the March 2021 Patch Tuesday, Microsoft released a set of seven DNS vulnerabilities. Five of the vulnerabilities are remote code execution (RCE) with critical CVSS (Common Vulnerability Scoring Standard) scores of 9.8, while the remaining two are denial of service (DoS). Microsoft shared detection guidance and proofs of concept with MAPP members for two of the RCE vulnerabilities, CVE-2021-26877 and CVE-2021-26897, which we have confirmed to be within the DNS Dynamic Zone Update activity. Microsoft subsequently confirmed that all seven of the DNS vulnerabilities are within the Dynamic Zone Update activity.

We confirmed from our analysis of CVE-2021-26877 and CVE-2021-26897, in addition to further clarification from Microsoft, that none of the five DNS RCE vulnerabilities are wormable.

RCE vulnerabilities
CVE-2021-26877, CVE-2021-26897 (exploitation more likely)
CVE-2021-26893, CVE-2021-26894, CVE-2021-26895 (exploitation less likely)

DoS vulnerabilities
CVE-2021-26896, CVE-2021-27063 (exploitation less likely)

A critical CVSS score of 9.8 means that an attacker can remotely compromise a DNS server with no authentication or user interaction required. Successful exploitation of these vulnerabilities would lead to RCE on a Primary Authoritative DNS server. While CVSS is a great tool for technical scoring, it needs to be taken in context with your DNS deployment environment to understand your risk which we discuss below.

We highly recommend you urgently patch your Windows DNS servers if you are using Dynamic Updates. If you cannot patch, we recommend you prioritize evaluating your exposure. In addition, we have developed signatures for CVE-2021-26877 and CVE-2021-26897 which are rated as “exploitation more likely” by Microsoft.

DNS Dynamic Updates, Threats and Deployment

Per the NIST “Secure Domain Name System (DNS) Deployment Guide”, DNS threats can be divided into Platform and Transaction Threats. The platform threats can be classed as either DNS Host Platform or DNS Software Threats. Per Table 1 below, Dynamic Update is one of the four DNS Transaction types. The seven DNS vulnerabilities are within the Dynamic Update DNS transaction feature of Windows DNS Software.

Table 1: DNS Transaction Threats and Security Objectives

The DNS Dynamic Zone Update feature allows a client to update its Resource Records (RRs) on a Primary DNS Authoritative Server, such as when it changes its IP address; these clients are typically Certificate Authority (CA) and DHCP servers. The Dynamic Zone Update feature can be deployed on a standalone DNS server or an Active Directory (AD) integrated DNS server. Best practice is to deploy DNS integrated with (AD) so it can avail itself of Microsoft security such as Kerberos and GSS-TSIG.

When creating a Zone on a DNS server there is an option to enable or disable DNS Dynamic Zone Updates. When DNS is deployed as a standalone server, the Dynamic Zone Update feature is disabled by default but can be enabled in secure/nonsecure mode. When DNS is deployed as AD integrated, the Dynamic Zone Update feature is enabled in secure mode by default.

Secure Dynamic Zone Update verifies that all RR updates are digitally signed using GSS-TSIG from a domain-joined machine. In addition, more granular controls can be applied on what principal can perform Dynamic Zone Updates.

Insecure Dynamic Zone Update allows any machine to update RRs without any authentication (not recommended).

Attack Pre-requisites

  • AD Integrated DNS Dynamic Updates (default config of secure updates)
    • A DNS server must accept write requests to at least one Zone (typically a primary DNS server only allows Zone RR writes but there are misconfigurations and secondary servers which can negate this)
    • Domain-joined machine
    • Attacker must craft request to DNS server and supply a target Zone in request
  • Standalone DNS Server (secure/nonsecure config)
    • A DNS server must accept write requests to at least one Zone (typically a primary DNS server only allows Zone RR writes but there are misconfigurations and secondary servers which can negate this) 
    • Attacker must craft request to DNS server and supply a target Zone in request 

From a Threat Model perspective, we must consider Threat Actor motives, capabilities, and access/opportunity, so you can understand the risk relative to your environment. We are not aware of any exploitation in the wild of these vulnerabilities so we must focus on the access capabilities, i.e., close the door on the threat actor opportunity. Table 2 summarizes DNS Dynamic Update deployment models relative to the opportunity these RCE vulnerabilities present.

Table 2: Threat Actor access relative to deployment models and system impact

The highest risk deployment would be a DNS server in Dynamic Update insecure mode exposed to the internet; this is not best security practice and based on our experience, we do not know of a use case for such deployment.

Deploying AD integrated DNS Dynamic Update in secure mode (default) mitigates the risk of an unauthenticated attacker but still has a high risk of a compromised domain computer or trusted insider being able to achieve RCE.

Vulnerability Analysis

All the vulnerabilities are related to the processing of Dynamic Update packets in dns.exe. The goal of our vulnerability analysis, as always for critical industry vulnerabilities, is to ensure we can generate accurate signatures to protect our customers.

Analysis of CVE-2021-26877

  • The vulnerability is triggered when a Zone is updated with a TXT RR that has a “TXT length” greater than “Data length” per Wireshark below:

Figure 1: Wireshark view of exploit packet classifying the DNS packet as malformed

  • The vulnerability is in the File_PlaceStringInFileBuffer() function as you can see from WinDbg output below:

Figure 2: WinDbg output of crash while attached to dns.exe

  • The vulnerability is an Out of bounds (OOB) read on the heap when the “TXT length” field of DNS Dynamic Zone Update is not validated relative to “Data length”. This could allow an attacker to read up to 255 bytes of memory. Microsoft states this vulnerability can be used to achieve RCE; this would require a further OOB write primitive.
  • The memory allocation related to the OOB read is created within the CopyWireRead() function. Relevant pseudo code for this function is below:

  • The File_PlaceStringInFileBuffer() function copies data from TXT_data allocated from CopyWireRead() function previously. However, the UpdateRR->TXT length value from Wireshark is not validated and used to copy from *UpdateRR->Data length. Because UpdateRR->TXT length is not validated relative to UpdateRR->Data length it results in a OOB read from heap memory.

Analysis of CVE-2021-26897

  • The vulnerability is triggered when many consecutive Signature RRs Dynamic Updates are sent
  • The vulnerability is an OOB write on the heap when combining the many consecutive Signature RR Dynamic Updates into base64-encoded strings before writing to the Zone file
  • Microsoft states this vulnerability can be used to achieve RCE

Figure 3: Packet containing many consecutive Signature RR dynamic updates. Pay special attention to the length field of the reassembled flow.

Exploitability

Exploiting these vulnerabilities remotely requires both read and write primitives in addition to bypassing Control Flow Guard (CFG) for execution. The DNS protocol has significant remote unauthenticated attack surface to facilitate generating such primitives which has been researched as part of CVE-2020-1350 (SigRed). In addition, per the RR_DispatchFuncForType() function, there are read and write functions as part of its dispatch table.

Figure 4: Path of DNS RR update packet

Figure 5: Dispatch functions for reading and writing

Mitigations

Patching is always the first and most effective course of action. If it’s not possible to patch, the best mitigation is to audit your DNS deployment configuration to limit Dynamic Zone Updates to trusted servers only. For those McAfee customers who are unable to deploy the Windows patch, the following Network Security Platform (NSP) signatures will provide a virtual patch against attempted exploitation of both vulnerabilities, CVE-2021-26877 and CVE-2021-26897 

NSP Attack ID: 0x4030e700 – DNS: Windows DNS Server Remote Code Execution Vulnerability (CVE-2021-26877)
NSP Attack ID: 0x4030e800 – DNS: Windows DNS Server Remote Code Execution Vulnerability (CVE-2021-26897)

In addition, NIST “Secure Domain Name System (DNS) Deployment Guide” provides best practices for securing DNS deployment such as:

  1. DNS Primary Server should restrict clients that can update RRs
  2. Secure Dynamic Update using GSS-TSIG
  3. Secondary DNS Server Dynamic Update forwarding restrictions using GSS-TSIG
  4. Fine-grained Dynamic Update restrictions using GSS-TSIG

The post Seven Windows Wonders – Critical Vulnerabilities in DNS Dynamic Updates appeared first on McAfee Blogs.

McAfee ATR Thinks in Graphs

8 March 2021 at 11:00

0. Introduction

John Lambert, a distinguished researcher specializing in threat intelligence at Microsoft, once said these words that changed perspectives: “Defenders think in lists. Attackers think in graphs.” This is true and, while it remains that way, attackers will win most of the time. However, the true power of graphs does not only reside in constructing them, but also in how we build them and what we do with them. For that, we need to reflect upon the nature of the data and how we can use graphs to make sense of it. I presented on this premise at the MITRE ATT&CKcon Power Hour held in January 2021.

At McAfee Advanced Threat Research (ATR), all threat intelligence relating to current campaigns, potential threats, and past and present attacks, is collated and normalized into a single truth, namely a highly redundant, scalable relational database instance, and disseminated into different categories, including but not limited to MITRE ATT&CK techniques involved, tools used, threat actor responsible, and countries and sectors targeted. This information is a subset of the data available in McAfee MVISION Insights. Much can be learned from looking at historical attack data, but how can we piece all this information together to identify new relationships between threats and attacks? We have been collecting and processing data for many years but identifying patterns quickly and making sense of the complete dataset as a whole has proven to be a real challenge.

In our recent efforts, we have embraced the analysis of threat intelligence using graphical representations. One key takeaway is that it is not just about mapping out intelligence about campaigns and threats into graphs; the strength lies in studying our datasets and applying graph algorithms to answer questions about the data.

In this paper, we provide an extensive description of the dataset derived from the threat intelligence we collect. We establish the methodology applied to validate our dataset and build our graphical representations. We then showcase the results obtained from our research journey as defenders thinking in graphs instead of lists.

The first section explains the kind of data we have at our disposal. The second section describes the goal of our research and the kind of questions we want to answer. Sections 3 and 4 establish the methodology used to process our dataset and to validate that we can actually do something useful with it by using graphs. The fifth section describes the process of building graphs, and Section 6 shows how we use these graphs to answer the questions laid out in Section 2. Section 7 introduces an additional research element to add more granularity to our experiment, and Section 8 shares the limitations of our research and potential ways to compensate for them. Sections 9 and 10 conclude this research with some reflections and proposed future work.

Section 1. Dataset

Our dataset consists of threat intelligence, either collected by or shared with our team, is piped into our internal MISP instance and published to relevant stakeholders. This data concerns information about campaigns, crimeware or nation-state attacks that are currently going on in the world, from potential or reoccurring threat (groups). The data is split into multiple categories used to establish everything we know about the four basic questions of what, who, where, and how. For example, certain attacks on countries in the Middle East have been conducted by the group MuddyWater and have targeted multiple companies from the oil and gas and telecom industries, leveraging spear phishing campaigns. The dataset used for this research is a collection of the answers to these four basic questions about each event.

Section 2. Research Goal

The quantity of data we have makes it almost impossible to make sense in one pass. Information is scattered across hundreds of events, in a database that does not necessarily enable us to connect each piece of information we have in relevant patterns. The goal of this research is to create a methodology for us to quickly connect and visualize information, identify patterns in our data that could reveal trends in, for example, actor behaviour or MITRE technique usage. In this paper, we specifically focus on actor trends and MITRE technique usage.

By providing such tooling, we can answer questions about frequency of actors or techniques, popularity of techniques across actors, and patterns of behaviour in technique usage among actors. These questions are laid out as such:

Frequency

  • Which techniques are observed most often?
  • Which actors are the most active?

Popularity

  • Which techniques are the most common across actors?

Patterns

  • Can we identify groups of actors using the same techniques?
  • Are actors using techniques in the same way?

These questions are not exhaustive of everything that can be achieved using this methodology, but they reveal an example of what is possible.

Section 3. Methodology

As we are proposing a way to build graphs to make sense of the data we have, we first need to validate our dataset to make sure graphs will deliver something useful. For that, we need to look at expected density and connectivity of the graph. Should our dataset be too dense and overly connected, building graphs will not result in something that can be made sense of.

After establishing that our dataset is graphable, we can focus on how exactly we will graph it. We need to establish what our nodes are and what defines our edges. In this case, we propose two representations: an event-centric view and actor-centric view, respectively taking events and actors as points of reference.

Once we have built our graphs, we investigate different techniques and algorithms to answer the questions laid out in the previous section. This experiment provides us insights into our data, but also into what we are missing from our data that could give us even more information.

The tooling used for this research is an internal tool referred to as Graph Playground that provides users with the possibility to build client-side undirected graphical visualizations in their browser, based on CSV or JSON files. This software also offers a toolbox with analysis techniques and algorithms to be used on the graphs.

Section 4. Dataset Validation

Before building proper graphical representations, we need to assess whether the dataset is a good fit. There are a few metrics that can indicate that the dataset is not necessarily fit for graphs, one of which being the average number of connections (edges) per node:

This average gives us an approximate indication of how many edges per node we can expect. Another useful metric is graph density, defined as the number of edges divided by the total number of possible edges for an undirected simple graph. This is normally calculated using the following formula:

It is a simple equation, but it can already give great insights as to what the graph is going to look like. A graph with high density might be a super connected graph where every node relates to one another in some way. It can be great for visualisation but will not provide us with anything useful when it comes to identifying patterns or differentiating between the different components of the graph.

Section 5. Building Graphs

Based on the data at hand, one intuitive way to build graphs is using a threat event as a central node and connected nodes that represent MITRE techniques, threat actors, tools, countries, and sectors to that event node.

Figure 1: Graph representation of the data

Figure 1 depicts the initial graphical representation using each event and associated metadata registered in MISP. Relationships between event nodes and other nodes are defined as follows: techniques and tools are used in one event that is attributed to a specific actor and involves a threat or attack on certain countries and sectors.

Based on the representation and our dataset, the number of nodes obtained is |N| = 1,359 and the total number of edges is |E| = 12,327. In our case, because only event nodes are connected to other nodes, if we want to check for the average number of edges per node, we need to look specifically at event nodes. In the obtained graph g, this average is equal to:

To calculate the density, we also need to account for the fact that only event nodes have connections. The density of the obtained graph g is then equal to:

Density always results in a number between 0 and 1. With an average of 18 edges per event node and a graph density of 0.053, we can expect the resulting graph to be relatively sparse.

Figure 2: Full representation of 705 MISP events

The full graph obtained with this representation in Figure 2, against our predictions, looks much denser than expected. It has an obvious central cluster that is busy with nodes that are highly interconnected, consisting mostly of event and technique nodes. In Figure 3, we discard MITRE technique nodes, leaving event, country, sector, and tool nodes, to demonstrate where the low-density calculation comes from.

Figure 3: Representation without MITRE technique nodes

Removing MITRE technique nodes results in a much less dense graph. This may be an indication that some event and technique nodes are highly interconnected, meaning there may be a lot of overlap between events and techniques used.

Figure 4: Representation with only event and MITRE technique nodes

Figure 4 proves this statement by showing us a large cluster of interconnected event and technique nodes. There is a set of events that all appear to be using the same technique. It would be interesting to isolate this cluster and take note of exactly which techniques these are, but this research takes us down another road.

Based on the data we have, which mostly consists of events relating to crimeware, we choose to disregard country and sector information in our graphical analyses. This is because these campaigns are most often sector and country-agnostic, based on historical observation. Therefore, we proceed without country and sector data. This allows us to perform some noise reduction, keeping events as points of reference.

We can also take this a step further and collapse event nodes to switch the focus to actor nodes with regard to tools and MITRE techniques used. This results in two different representations derived from the original graph.

Section 5.1 Event-centric View

Removing country and sector nodes, we are left with event nodes connected to actor, technique, and tool nodes. Figure 5 illustrates this representation.

Figure 5: Representation without country and sector nodes

This resulting representation is an event-centric view, and it can help us answer specific questions about frequency of actors involved, techniques or tools used during recorded attacks and campaigns.

Figure 6: Event-centric view

The graph in Figure 6 is very similar to the original one in Figure 2, but the noise that is not of real interest at this stage has been removed, so that we can really focus on events regarding actors, techniques, and tools.

Section 5.2 Actor-centric View

Another possible representation, because the data we have about countries and sectors is very sparse, is to center the graph around actor nodes, connected to techniques and tools.

Figure 7: Collapsed presentation of actors, techniques, and tools

Figure 7 establishes the relationship between the three remaining nodes: actor, technique, and tools. The resulting graph is displayed in Figure 8.

Figure 8: Actor-centric view

These two ways to build graphs based on our data provide an event-centric view and an actor-centric view and can be used to answer different questions about the gathered intelligence.

Section 6. Using the Graphs

Based on the two generated views for our data, we demonstrate how certain algorithms and graph-related techniques can be used to answer the questions posed in Section 2. Each view provides insights on frequency, popularity, or pattern questions.

Section 6.1 Frequency Analysis

Which techniques are observed most often?

To answer questions about the frequency of techniques used, we need to take the event-centric view, because we are directly addressing how often we have observed techniques being used. Therefore, we take this view and look at the degree of nodes in the graph. Nodes with a high degree are nodes with more connections. A MITRE technique node with a very high degree is a node that is connected to a high number of events.

Figure 9: Degree analysis on the event-centric view with a focus on techniques

Figure 9 shows us the application of degree analysis on the event-centric view, revealing techniques like Spearphishing Attachment and Obfuscated Files or Information as the most often observed techniques.

Which actors are the most active?

The same degree analysis can be used on this view to identify which actors have most often been recorded.

Figure 10: Degree analysis on the event-centric view with a focus on actors

Based on the results displayed in Figure 10, Sofacy, Lazarus Group, and COVELLITE are the most recorded actors across our data.

Section 6.2 Popularity Analysis

Which techniques are the most common across actors?

To answer questions about popularity of techniques across actors, we need to look at the actor-centric view, because it will show us how techniques and actors relate to one another. While degree analysis would also work, we can make use of centrality algorithms that measure how much control a certain node has over a network, or in other terms: how popular a certain node is.

Figure 11: Centrality algorithm used on the actor-centric view

Running centrality algorithms on the graph shows us that Obfuscated Files or Information and User Execution are two of the most popular techniques observed across actors.

6.3 Patterns Identification

Can we identify groups of actors using the same techniques?

The keyword here is groups of actors, which insinuates that we are looking for clusters. To identify groups of actors who use the same techniques, we can attempt to use clustering algorithms to isolate actors who behave the same way. We need to apply these algorithms on the actor-centric view. However, we also see that our actor-centric view in Figure 8 has quite a dense bundle of nodes, and this could make the building of clusters more difficult.

Figure 12: Clustering algorithm used on the actor-centric view

Louvain Clustering is a community detection technique that builds clusters based on edge density; Figure 12 shows us the results of running this algorithm. We see that it was possible to build some clusters, with a clear distinction between the orange cluster and the bundle of nodes, but it is not possible to verify how accurate our clusters are, because of the density of the subgraph where all the nodes seem to be interconnected.

We can draw two conclusions from this:

  1. A lot of actors use the same techniques.
  2. We need to introduce additional information if we want to dismember the dense bundle of nodes.

This takes us to the last important question:

Are actors using techniques in the same way?

With the information currently at our disposal, we cannot really assess whether a technique was used in the same way. It would be ideal to specify how an actor used a certain technique and encode that into our graphs. In the next section, we introduce an additional element to hopefully provide more granularity so we can better differentiate actors.

Section 7. Introducing Killchain Information

To provide more granularity and hopefully answer the question about actors using techniques in the same way, we embed killchain step information into our graphs. A certain attack can be used for multiple killchain steps. We believe that adding killchain step information to specify where an attack is used can help us better differentiate between actors.

Figure 13: Representation that introduces a killchain step node

This is a slight modification that occurs on our actor-centric view. The resulting graph should provide us with more granularity with regards to how a technique, that is present at multiple steps, was really used.

Figure 14: Actor-centric view with killchain information

The resulting graph displayed in Figure 14 is, for lack of a better word, disappointing. That is because killchain step information has not provided us with more granularity, which in turn is because of our dataset. Unfortunately, MISP does not let users specify when a technique is used in one specific step of the killchain, if that technique can occur in multiple steps. When recording an observed MITRE technique that can occur in multiple steps, all steps will be recorded with that technique.

Section 8. Limitations

MISP provides granularity in terms of MITRE sub-techniques, but there is no built-in differentiation on the killchain steps. It is not yet possible to specify exactly at which step a technique present in multiple steps is used. This removes a certain level of granularity that could be useful in the actor-centric view to differentiate even more between actors. If such differentiation existed, the actor-centric view could be collapsed into:

Additionally, based on the data at hand, it is clear that actors tend to use the same techniques overall. The question of whether using MITRE techniques to differentiate between actors is actually useful then comes to mind. Perhaps it can be used to discard some noticeably different actors, but not most?

Limitations of our research also lie in the tooling used. The Graph Playground is great for quick analyses, but more extensive manipulations and work would require a more malleable engine.

Lastly, our research focused on MISP events, threat actors, and MITRE techniques. While most questions about frequency, popularity, and pattern recognition can be answered the same way for tools, and even country and sector, the list of what is achievable with graphs is definitely not exhaustive.

Section 9. Conclusion

Building graphs the right way helps us visualize our large dataset almost instantly, and it helps us make sense of the data we see. In our case, right means the way that is most relevant to our purpose. By having sensical and relevant representations, we can connect cyber threats, campaigns, and attacks to threat actors involved, MITRE techniques used, and more.

Graphical representations are not just about piping all our data into one visualization. We need to think of how we should build our graphs to get the most out of them, while attempting to maintain satisfactory performance when scaling those graphs. Graphs with thousands of nodes often take long to render, depending on the visualization engine. The Graph Playground generates graphs from a file on the client-side, in the browser. This makes the generation incredibly fast.

Certain aspects of our research require an event-centric view, while others may, for example, require an actor-centric view. We also need to assess whether building graphs is useful in the first place. Highly dense and connected data will result in graphs that cannot be used for anything particularly interesting for our analyses of threat intelligence.

Our research has proven fruitful in the sense that much can be gained from translating our dataset to adequate representations. However, we lack a certain granularity-level that could help us differentiate between certain aspects of our data even more.

To add to John Lambert’s quote, “Defenders think in lists. Attackers think in graphs. And Threat Intelligence analysts build proper graphs and exhaustively use them.

Section 10. Future Work

As mentioned, we have encountered a granularity issue that is worth looking into for future research. It would be interesting to consider incorporating analysis results from EDR engines, to isolate where a specific MITRE ATT&CK technique was used. This would provide much deeper insights and potentially even more data we can include in our visualizations. Should we succeed and process this information into our graphs, we would be able to better differentiate between actors that otherwise seem to behave the same.

We can also shift our perspective and include country and sector information but, for that, we need to exclude all crimeware-related events that are sector or country-agnostic and include only campaigns that have specific targets. Only then will such representation be useful for further analysis.

Another point worth mentioning for future work would be to consider incorporating additional resources. The Intezer OST Map, which is open source, provides insights on tools used by threat actors for well-known campaigns. It would be interesting to merge the Intezer dataset with our own and experiment with our graph representations based on this new dataset.

The post McAfee ATR Thinks in Graphs appeared first on McAfee Blogs.

Ripple20 Vulnerability Mitigation Best Practices

22 June 2020 at 22:32

On June 16th, the Department of Homeland Security and CISA ICS-CERT issued a critical security advisory warning covering multiple newly discovered vulnerabilities affecting Internet-connected devices manufactured by multiple vendors. This set of 19 vulnerabilities in a low-level TCP/IP software library developed by Treck has been dubbed “Ripple20” by researchers from JSOF.

A networking stack is a software component that provides network connectivity over the standard internet protocols. In this specific case these protocols include ARP, IP (versions 4 and 6), ICMPv4, UDP and TCP communications protocols, as well as the DNS and DHCP application protocols. The Treck networking stack is used across a broad range of industries (medical, government, academia, utilities, etc.), from a broad range of device manufacturers – a fact which enhances their impact and scope, as each manufacturer needs to push an update for their devices independently of all others. In other words, the impact ripples out across the industry due to complexities in the supply and design chains.

Identifying vulnerable devices on your network is a crucial step in assessing the risk of Ripple20 to your organization. While a simple Shodan search for “treck” shows approximately 1000 devices, which are highly likely to be internet-facing vulnerable devices, this represents only a fraction of the impacted devices. Identification of the Treck networking stack vs. other networking stacks (such as the native Linux or Windows stacks) requires detailed analysis and fingerprinting techniques based on the results of network scans of the devices in question.

The impact of these vulnerabilities ranges from denial of service to full remote code exploitation over the internet, with at least one case not requiring any authentication (CVE-2020-11901). JSOF researchers identified that these vulnerabilities impact a combination of traditional and IoT devices. Customers should review advisories from vendors such as Intel and HP because non-IoT devices may be running firmware that makes use of the Treck networking stack.

Ripple20’s most significant impact is to devices whose network stack is exposed (in general IoT devices incorporating the Treck network stack) as compared to devices that incorporate the stack that it is only exposed to the local device. We recommend that you audit all network-enabled devices to determine if they are susceptible to these vulnerabilities.

There are potentially tens of millions of devices that are vulnerable to at least one of the Ripple20 flaws. Mitigating impact requires attention from both device owners and device vendors.

Mitigations for users of vulnerable devices per CISA recommendations (where possible): 

  • Patch any device for which a vendor has released an update.
  • Practice the principle of least privilege for all users and devices (devices and users should only have access to the set of capabilities needed to accomplish their job). In this case, minimize network exposure and internet-accessibility for all control system devices.
  • Locate control system networks and remote devices behind firewalls and isolate them from the business network.
  • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that a VPN is only as secure as the connected devices. VPN solutions should use multi-factor authentication.
  • Use caching DNS servers in your organization, prohibiting direct DNS queries to the internet. Ideally, caching DNS servers should utilize DNS-over-HTTPS for lookups.
  • Block anomalous IP traffic by utilizing a combination of firewalls and intrusion prevention systems.

Where Can I Go to Get More Information?

Please review KB93020 for more information and subscribe for updates.

The post Ripple20 Vulnerability Mitigation Best Practices appeared first on McAfee Blogs.

What’s in the Box? Part II: Hacking the iParcelBox

18 June 2020 at 07:01

Package delivery is just one of those things we take for granted these days. This is especially true in the age of Coronavirus, where e-commerce and at-home deliveries make up a growing portion of consumer buying habits.

In 2019, McAfee Advanced Threat Research (ATR) conducted a vulnerability research project on a secure home package delivery product, known as BoxLock. The corresponding blog can be found here and highlights a vulnerability we found in the Bluetooth Low Energy (BLE) configuration used by the device. Ultimately, the flaw allowed us to unlock any BoxLock in Bluetooth range with a standard app from the Apple or Google store.

Shortly after we released this blog, a similar product company based in the UK reached out to the primary researcher (Sam Quinn) here at McAfee ATR, requesting that the team perform research analysis on his product, called the iParcelBox. This device is comprised of a secure steel container with a push-button on the outside, allowing for package couriers to request access to the delivery container with a simple button press, notifying the homeowner via the app and allowing remote open/close functions.

iParcelBox – Secure Package Delivery & iParcelBox App

The researcher was able to take a unique spin on this project by performing OSINT (Open Source Intelligence), which is the practice of using publicly available information, often unintentionally publicized, to compromise a device, system or user. In this case, the primary developer for the product wasn’t practicing secure data hygiene for his online posts, which allowed the researcher to discover information that dramatically shortened what would have been a much more complicated project. He discovered administrative credentials and corresponding internal design and configurations, effectively providing the team access to any and all iParcelBox devices worldwide, including the ability to unlock any device at a whim. All test cases were executed on lab devices owned by the team or approved by iParcelBox. Further details of the entire research process can be found in the full technical version of the research blog here.

The actual internals of the system were well-designed from a security perspective, utilizing concepts like SSL for encryption, disabling hardware debugging, and performing proper authentication checks. Unfortunately, this level of design and security were all undermined by the simple fact that credentials were not properly protected online. Armed with these credentials the researcher was able to extract sensitive certificates, keys, device passwords, and WIFI passwords off any iParcelBox.

Secondly, as the researcher prepared the writeup on the OSINT techniques used for this, he made a further discovery. When analyzing the configuration used by the Android app to interact with the cloud-based IOT framework (AWS-IOT), he found that even without an administrative password, he could leak plaintext temporary credentials to query the AWS database. These credentials had a permission misconfiguration which allowed the researcher to query all the information about any iParcelBox device and to become the primary owner.

In both cases, to target a device, an attacker would need to know the MAC address of the victim’s iParcelBox; however, the iParcelBox MAC addresses appeared to be generated non-randomly and were simple to guess.

A typical research effort for McAfee ATR involves complex hardware analysis, reverse engineering, exploit development and much more. While the developer made some high-level mistakes regarding configuration and data hygiene, we want to take a moment to recognize the level of effort put into both physical and digital security. iParcelBox implemented numerous security concepts that are uncommon for IOT devices and significantly raise the bar for attackers. It’s much easier to fix issues like leaked passwords or basic configuration issues than to rebuild hardware or reprogram software to bolt on security after the fact. This may be why the company was able to fix both issues almost immediately after we informed them in March of 2020. We’re thrilled to see more and more companies of all sizes embracing the security research community and collaborating quickly to improve their products, even from the beginning of the development cycle.

What can be done?

For consumers:

Even developers are subject to the same issues we all have; choosing secure and complex passwords, protecting important credentials, practicing security hygiene, and choosing secure configurations when implementing controls for a device. As always, we encourage you to evaluate the vendor’s approach to security. Do they embrace and encourage vulnerability research on their products? How quick are they to implement fixes and are they done correctly? Nearly every product on the market will have security flaws if you look hard enough, but the way they are handled is arguably more important than the flaws themselves.

For developers and vendors:

This case study should provide a valuable testament to the power of community. Don’t be afraid to engage security researchers and embrace the discovery of vulnerabilities. The more critical the finding, the better! Work with researchers or research companies that practice responsible disclosure, such as McAfee ATR. Additionally, it can be easy to overlook the simple things such as the unintentional leak of critical data found during this project. A security checklist should include both complex and simple steps to ensure the product maintains proper security controls and essential data is protected and periodically audited.

The post What’s in the Box? Part II: Hacking the iParcelBox appeared first on McAfee Blogs.

My Adventures Hacking the iParcelBox

18 June 2020 at 07:01

In 2019, McAfee Advanced Threat Research (ATR) disclosed a vulnerability in a product called BoxLock. Sometime after this, the CEO of iParcelBox, a U.K. company, reached out to us and offered to send a few of their products to test. While this isn’t the typical M.O. for our research we applaud the company for being proactive in their security efforts and so, as the team over at iParcelBox were kind enough to get everything shipped over to us, we decided to take a look.

The iParcelBox is a large steel box that package couriers, neighbors, etc. can access to retrieve or deliver items securely without needing to enter your home. The iParcelBox has a single button on it that when pushed will notify the owner that someone wants to place an object inside. The owner will get an “open” request push notification on their mobile device, which they can either accept or deny.

The iParcelBox (Photo Credit: iparcelbox.com)

Recon

The first thing we noticed about this device is the simplicity of it. In the mindset of an attacker, we are always looking at a wide variety of attack vectors. This device only has three external vectors: remote cloud APIs, WIFI, and a single physical button.

iParcelBox Delivery Button (Photo Credit: iparcelbox.com)

During setup the iParcelBox creates a WIFI access point for the mobile application to connect with and send setup information. Each iParcelBox has a unique randomly generated 16-character WiFi password that makes brute forcing the WPA2 key out of the question; additionally, this Access Point is only available when the iParcelBox is in setup mode. The iParcelBox can be placed into setup mode by holding the button down but it will warn the owner via a notification and will only remain in setup mode for a few minutes before returning to normal operation.

iParcelBox Random WiFi Access Point Password (16 Characters)

Since we have the WiFi password for the iParcelBox in our lab, we connected to the device to see what we could glean from the webserver. The device was only listening on port 443, meaning that the traffic between the application and iParcelBox was most likely encrypted, which we later verified. This pointed us to the Android app to try to decipher what type of messages were being sent to the iParcelBox during setup.

iParcelBox Port Scan

Using dex2jar we were able to disassemble the APK file and look at the code within the app. We noticed quickly that the iParcelBox was using MQTT (MQ Telemetry Transport) for passing messages back and forth between the iParcelBox and the cloud. MQTT is a publish/subscribe message protocol where devices can subscribe to “topics” and receive messages. A simple description can be found here: (https://youtu.be/EIxdz-2rhLs)

Dex2Jar Command

A typical next step is to retrieve the firmware for the device, so we started to look through the disassembled APK code for interesting URLs. While we didn’t find any direct firmware links, we were able to find some useful information.

Disassembled Code pulled from APK

The code snipped above shows a few interesting points, including the string “config.iparcelbox.com” as well as the line with “app” and “TBpwkjoU68M”. We thought that this could be credentials for an app user passed to the iParcelBox during setup; however, we’ll come back to this later. The URL didn’t resolve on the internet, but when connecting to the iParcelBox access point and doing a Dig query we were able to see that it resolves to the iParcelBox.

DNS Lookup of config.iparcelbox.com

Nothing from the Android app or the webserver on the device popped out to us so we decided to look deeper. One of the most common ways that information about targets can be gathered is by looking through user forums and seeing if there are others trying to tweak and modify the device. Often with IOT devices, home automation forums have numerous examples of API usage as well as user scripts to interact with such devices. We wanted to see if there was anything like this for the iParcelBox. Our initial search for iParcelBox came up empty, other than some marketing content, but when the search was changed to iParcelBox API, we noticed a few interesting posts.

Google Search for “iparcelbox api”

We could see that even on the first page there are a few bug reports and a couple of user forums for “Mongoose-OS”. After going to the Mongoose-OS forums we could clearly see that one user was a part of the iParcelBox development team. This gave us some insight that the device was running Mongoose-OS on an ESP32 Development board, which is important since an ESP32 device can be flashed with many other types of code. We started to track the user’s posts and were able to discover extensive information about the device and the development decisions throughout the building process. Most importantly this served as a shortcut to many of the remaining analysis techniques.

As mentioned earlier, a high priority is to try to gain access to the device’s firmware by either pulling it from the device directly or by downloading it from the vendor’s site. Pulling firmware is slightly more tedious since you must often solder wires to the flash chip or remove the chip all-together to interface with the flash. Before we began to attempt to pull the firmware from the ESP32, we noticed another post within the forums that mentioned that the flash memory on the device was encrypted.

Post describing flash encryption

With this knowledge, we skipped soldering wires to the ESP32 and didn’t even try to pull the firmware manually since it would have proven difficult to get anything off it. This also gave us insight into the provisioning process and how each device is set up. With this knowledge we started to look for how the OTA updates are downloaded.

Searching around a little longer we were able to find a file upload of a large log file containing what seemed like the iParcelBox boot procedure. Searching through the log we found some highly sensitive data.

Admin Credentials and gh-token from boot log

In the snippet above you can see that the admin credentials are passed as well as the GitHub token. Needless to say, this isn’t good practice, we will see if we can use that later. But in this log, we also found a firmware URL.

Firmware URL from boot log

However, the URL required a username and password.

Firmware.iparcelbox.com .htaccess

We found this forum post where “.htaccess” is set up to prevent unintended access to the firmware download.

.htaccess post

The admin password found earlier didn’t authenticate, so we wanted to get the logs off the device to see if these were old credentials and if we could print the new credentials out to UART.

The internals of the iParcelBox (TX and RX highlighted in red)

The ESP32 RX and TX pins are mapped to the USB-C connection, but if you look at the circuit there is no FTDI (Future Technology Devices International) chip to do processing, so this is just raw serial. We decided to just solder to the vias (Vertical Interconnect Access) highlighted in red above, but still no data was transferred.

Then we started to search those overly helpful forum postings again, and quickly found the reason.

Disable UART

This at least verified that it wasn’t something that we set up incorrectly, but rather that logging was simply disabled over UART.

Method #1 – RPC

From our recon work we pretty much settled on the fact that we were not going to get into the iParcelBox easily from a physical standpoint and decided to switch a network approach. We knew that during setup the iParcelBox creates a wireless AP and that we can connect to it. Armed with our knowledge from the forums we decided to revisit the web server on the iParcelBox. We began by sending some “MOS” (Mongoose-OS) control commands to see what stuck.

Setup instructions for Mongoose-OS can be found here. Instead of installing directly to the OS we did it in Docker for portability.

Docker file used to create mos

Referencing the forums provided several examples of how to use the mos command.

Docker mos commands

The first command returned a promising message that we just need to supply credentials. Remember when we found the boot log earlier? Yep, the admin credentials were posted online, and they actually work!

At this point we had full effective root access to the iParcelBox including access to all the files, JavaScript code, and even more importantly, the AWS certificate and private key.

With the files extracted from the device we noticed that the developers at iParcelBox implemented an Access Control List (ACL). For an IOT device this is uncommon but a good practice.

ACL showing users permissions

The credentials we found earlier in the disassembled Android APK with the username “app” were RPC credentials but with limited permissions to only run Sys.GetInfo, Wifi.Scan, Wifi.PortalSave and Sys.Reboot. Nothing too interesting can be done with those credentials, so for the rest of this method we will stick with the “admin” credentials.

Now that we have the credentials, certificates, and private keys we wanted to try to pivot to other devices. During setup we noticed that the MAC address was labeled “TopicID.”

Setup process linking MAC Address to the TopicID

As we determined earlier, the iParcelBox uses MQTT for brokering the communication between the device, cloud, and mobile application. We were interested to find out if there were any authentication barriers in place, or if all you need is the MAC address of the device to initiate commands remotely.

Since we essentially had root access, enabling logging was a logical next step so we could see what was happening on the device. From one of the Mongoose-OS forums posts we saw that you can enable UDP logging to a local device by changing the configuration on the iParcelBox.

How to enable UDP logging post

We provisioned the iParcelBox, then held the button down until we entered setup mode (where the AP was available), thus reenabling RPC calls. Then we set the “udp_log_addr” to our local machine.

Reenabling Logging on iParcelBox

Now we have logs and much more information. We wanted to test if we could access the MQTT broker and modify other iParcelBoxes. In the logs we were able to validate that the MQTT broker was setup on AWS IOT and was using the certificate and keys that we pulled earlier. We found some Python examples of connecting to the AWS MQTT broker (https://github.com/aws/aws-iot-device-sdk-python) but it assumed it knows the full topic path (e.g. topic_id/command/unlock).

UDP Log file

Parsing through the extracted logs from UDP, we were able to find the format for the “shadow/update” MQTT topic. However, when trying to subscribe to it with the Python script, it seemed to connect to the MQTT broker, but we couldn’t ever get any messages to send or receive. Our best guess is that it was limited to one subscribe per topic or that our code was broken.

We went searching for another way to control devices. This brought us back to the Mongoose-OS forum (seeing a pattern here?). We found this post explaining that the devices can run RPC commands over MQTT.

RPC over MQTT

This would be better for an attacker than only MQTT access, since this gives full access to the device including certificates, keys, user configuration files, WIFI passwords, and more. We could also use RPC to write custom code or custom firmware at this point.  We found the official Mongoose-OS support for this here (https://github.com/mongoose-os-libs/rpc-mqtt), to which they even included an example with AWS IOT.

After plugging that into the “mos” command we were able to run all administrative RPC commands on the device that we pulled the keys from, but also any other device that we knew the MAC address of.

Running RPC commands on multiple ATR lab devices

From looking at the two iParcelBoxes that were sent to us, the MAC addresses are only slightly different and strongly suggest that they are probably generated incrementally.

  • 30AEA4C59D30
  • 30AEA4C59D6C

Theoretically, with the MAC addresses incremental we could have just written a simple script to iterate through each of the iParcelBoxes’ MAC addresses, found any iParcelBox connected to the internet, and controlled or modified them in any way we wanted. However, the most common attack would likely be a more targeted one, where the attacker was looking to steal a package or even a victim’s home WiFi credentials. An attacker could do a simple network scan to find the MAC address of the target iParcelbox using a tool like “airodump-ng”. Then, after the attacker knows the target MAC address, they could use the admin credentials to initiate a “mos” command over MQTT and execute a “GPIO.Toggle” command directed at the GPIO (General Purpose Input Output) pin that controls the locking mechanism on the iParcelBox. A toggle will invert the state, so if the iParcelBox is locked, a GPIO toggle will unlock the box. If the attacker had other motives, they could also initiate a config dump to gain access to the WiFi credentials to which the iParcelBox is connected.

Scanning for iParcelBoxes and Controlling them with RPC

Method #2 – AWS Misconfiguration

While writing this blog we wanted to double check that SSL pinning was done properly. After we saw this post during our recon, we assumed it was pinning a certificate. We set up an Android with a certificate unpinner using Frida.  With the unpinner installed and working we were able to decrypt traffic between the application and the AWS servers, but it failed to decrypt the data from application to the iParcelBox. Please follow this technique if you’d like to learn how you can unpin certificates on Android devices.

Next, we reran the iParcelBox application without the Frida SSL Unpinner, which returned the same AWS server transactions, meaning that pinning wasn’t enabled. We browsed through some of the captures and found some interesting requests.

Cognito Credential SSL Network Capture

The “credentials” in the capture immediately piqued our interest. They are returned by a service called “Cognito”, which is an AWS service allowing apps and users to access resources within the AWS ecosystem for short periods of time and with limited access to private resources.

AWS Cognito example (Photo Credit: Amazon.com)

When an application wants to access an AWS service, it can ask for temporary credentials for the specific task. If the permissions are configured correctly, the credentials issued by the Cognito service will allow the application or user to complete that one task and deny all other uses of the credentials to other services.

To use these credentials, we needed the AWS-CLI interface. Thankfully, Amazon even has a Docker image for AWS-CLI which made things much easier for us. We just saved the credentials returned from the Cognito service inside of a “~/.aws” folder. Then we checked what role these credentials were given.

AWS-CLI docker command

The credentials captured from the Android application were given the “AppAuth_Role”. To find out what the “AppAuth_Role” had access to we then ran a cloud service enumeration using the credentials; the scripts can be found here (https://github.com/NotSoSecure/cloud-service-enum) and are provided by the NotSoSecure team. The AWS script didn’t find any significant security holes and showed that the credentials were properly secured. However, looking at the next few network captures we noticed that these credentials were being used to access the DynamoDB database.

Checking if the user is subscribed to the Premium service

Getting the owner’s devices

After reading through some of the DynamoDB documentation we were able to craft database queries.

DynamoDB Query

Because the “primary key” for the database is the “DeviceID” which we know is just the MAC address of the iParcelBox, we can then modify this query and get any other device’s database entries. While we didn’t test this for ethical reasons, we suspect that we could have used this information to gain access to the MQTT services. We also did not attempt to write to the database since this was a live production database and we didn’t want to corrupt any data.

We investigated the Android application attempting to trigger some more database interactions to see what other queries were being sent, but were limited to the following:

  • Accounts – Shows premium subscription info
  • Owners – Shows devices and guests of each iParcelBox
  • Users – Used to save owners of each iParcelBox (only during setup)

With our self-imposed database write restrictions, none of these tables really helped us anyway. That is when we began looking at the disassembled code of the Android app for more clues. Since we now knew the table names, we searched for “ClientID”, which turned up the Java file “DBConstants.class.”

Constants file from APK

This constants file gave us information that there are more database tables and fields, even though we never saw them in the network traffic. The “TABLE_DEVICES_PASSWORD” caught our eyes from the “iParcelBox_devices” table.

We tested the “AppAuth_Role” credentials on this table as well, which was accepted.

Requesting information from the iParcelBox_devices table

We were able to get the device password and serial number all from the MAC address. Recall the “iParcelBox Setup Information” image at the beginning of the blog and how it mentions that you should keep this information safe. The reason that this information should be kept safe is that you can become the owner of the iParcelBox if you know the MAC address, serial number, and password even without the QR code thanks to the “Add Manually” button.

“Add manually” option during setup

With this information an attacker could register for a new iParcelBox account, login to the application, capture the Cognito credentials, begin the “setup” process, click “Add Manually” and then enter all the required information returned from the database to gain full control over any iParcelBox. This could all take place from simply knowing the MAC address since the “AppAuth_Role” can read any database entry.

Required Information to set up the iParcelBox

Lessons Learned

This project took a turn from a classic hardware/IOT device research project to an OSINT research topic very early on. It really goes to show that even simple mistakes with online data hygiene could expose key details to attackers allowing them to narrow down attack vectors or expose sensitive information like credentials.

Since this was a sponsored project from iParcelBox, we reported this to the company immediately. They promptly changed the admin password for every iParcelBox and asked the developers at Mongoose-OS to implement a change where one device’s AWS certificate and private key cannot control any other device. This was patched within 12 hours after our vendor disclosure, which puts iParcelBox in the top response time for a patch that we have ever seen. We have tested the patch and can no longer control other devices or use the old admin password to access the devices from within setup mode.

iParcelBox also fixed the Android application not pinning certificates properly and removed all direct calls to the DynamoDB. We were still able to decrypt some traffic using the Frida SSL unpinner, but the application would freeze, which we believe is due to the MQTT broker not accepting a custom certificate. The DynamoDB queries are now wrapped in API calls which also check against the customer ID. This prevents someone from using their extracted Cognito credentials to obtain information from any device other than their own. Wrapping the database queries within API calls is an effective security fix as well, as the data can be parsed, verified, and sanitized all before committing to the database.

We wanted to give props to the team at iParcelBox for their focus on security throughout the development of this product. It is easy to see from the device and the forum posts that the developers have been trying to make this device secure from the start and have done it well. All non-essential features like UART and Bluetooth are turned off by default and a focus on data protection is clearly there as evidenced through the use of SSL and encryption of the flash memory. There are not many attack surfaces that an attacker could leverage from the device and is a great refreshment to see IOT devices heading this direction.

The post My Adventures Hacking the iParcelBox appeared first on McAfee Blogs.

RagnarLocker Ransomware Threatens to Release Confidential Information

9 June 2020 at 16:21
Ransomware

EXECUTIVE SUMMARY

The RagnarLocker ransomware first appeared in the wild at the end of December 2019 as part of a campaign against compromised networks targeted by its operators.

The ransomware code is small (only 48kb after the protection in its custom packer is removed) and coded in a high programming language (C/C++). Like all ransomware, the goal of this malware is to encrypt all files that it can and request a ransom for decrypting them.

RagnarLocker’s operators, as we have seen with other bad actors recently, threaten to publish the information they get from compromised machines if ransoms are not paid.

After conducting reconnaissance, the ransomware operators enter the victim’s network and, in some pre-deployment stages, steal information before finally dropping the ransomware that will encrypt all files in the victim’s machines.

The most notable RagnarLocker attack to date saw this malware deployed in a large company where the malware operators then requested a ransom of close to $11 million USD in return for not leaking information stolen from the company. In this report we will talk about the sample used in this attack.

At the time of writing there are no free decryptors for RagnarLocker.

However, certain McAfee products, including personal antivirus, endpoint, and gateway can protect our customers against the threats that we talk about in this report.

RAGNARLOCKER OVERVIEW

The unpacked malware is a binary file of 32 bits that can be found as an EXE file.

FIGURE 1. INFORMATION ABOUT THE MALWARE

As can be seen in the previous screenshot, this sample was compiled on the 6th of April 2020. The attack mentioned earlier took place some days later, but this sample was prepared for the victim, as we will explain later.

Name malware.exe
Size 48,460 bytes unpacked (can change between samples), packed can be variable
File-Type EXE 32 bits (can change between samples)
SHA 256 7af61ce420051640c50b0e73e718dd8c55dddfcb58917a3bead9d3ece2f3e929
SHA 1 60747604d54a18c4e4dc1a2c209e77a793e64dde
Compile time 06-04-2020 (can change between samples)

 

TECHNICAL DETAILS

As we often see with ransomware, RagnarLocker starts preparing some strings of languages for the CIS countries that are embedded within its own code (in Unicode).

FIGURE 2. THE LANGUAGE STRINGS EMBEDDED INTO THE CODE IN THE STACK

The languages that are hardcoded are:

Georgian
Russian
Ukrainian
Moldavian
Belorussian
Azerbaijani
Turkmen
Kyrgyz
Kazakh
Uzbek
Tajik

 

After preparing these strings, the malware uses the function “GetLocaleInfoW” to get the LOCALE_SYSTEM_DEFAULT language as a string. Once obtained, it will check the system language with the blacklisted languages and, if any of them match, it will terminate itself with the function “TerminateProcess” and with an error result code of 0x29A (as we have seen before with many different malware samples).

FIGURE 3. CHECK OF THE LANGUAGE AGAINST THE BLACKLIST

The check against the LOCALE_SYSTEM_DEFAULT is to prevent a user from installing a language they would not otherwise use as a means of avoiding infection. The check is made against the language selected in Windows. Of course, not everyone in these countries will be using a CIS language in Windows so English is also ok to use. As with other ransomware families, there is no guarantee that infection will be avoided if other languages are selected as the default.

After this the malware will get the name of the infected computer with the function “GetComputerNameW” and the username of whoever is actively using the machine at that time with the function “GetUserNameW”.

FIGURE 4. GET THE COMPUTER NAME AND THE USERNAME

After this the malware will read two registry keys:

  • HKLM\SOFTWARE\Microsoft\Cryptography and the subkey MachineGuid to get the GUID of the victim machine.
  • HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion and the subkey “ProductName” to get the name of the operating system.

For this the malware uses the functions “RegOpenKeyExW”, “RegQueryValueExW” and “RegCloseKey” in the hive HKEY_LOCAL_MACHINE. This hive can be read without admin rights.

FIGURE 5. READ FROM THE REGISTRY THE NAME OF OPERATING SYSTEM AND GUID

Next, RagnarLocker will prepare the first string in the stack with the function “lstrcpyW” and later will start joining the strings with the function “lstrcatW”.

The sequence is first the GUID of the machine, then the Windows operating system name, the user logged in the machine and, finally, the name of the victim machine.

FIGURE 6. GET INFORMATION OF THE USER AND MACHINE AND JOIN ALL STRINGS

In the screenshot some values were modified to protect my virtual machine. After getting this information and preparing the string, the malware makes a custom hash with each.

For this, the malware will reserve some memory with “VirtualAlloc” and get the size of the string and compute the hash in a very small loop. After this it will format the hash with the function “wsprintfW” to have it as a Unicode string.

FIGURE 7. MAKE THE CUSTOM HASH AND FORMAT AS UNICODE STRING

The hashes are made in the following order:

  • Machine name (g. 0xf843256f*)
  • Name of the user logged into the machine (e.g. 0x56ef3218*)
  • GUID of the infected machine (e.g. 0x78ef216f*)
  • Name of the operating system (e.g. 0x91fffe45*)
  • Finally, the full string with all strings joined (e.g. 0xe35d68fe*)

*The above values have been changed to protect my machine.

After this it will use the function “wsprintfW”, with the template string “%s-%s-%s-%s-%s”, to format the custom hashes together with hyphens between them, but in this case the hashes are in this order:

  • GUID
  • Operating System Name
  • Name of the logged in user
  • Name of the infected machine
  • Full string with all other strings joined together

FIGURE 8. CREATE CUSTOM HASH OF THE STRINGS AND FORMAT THE FINAL STRING IN A SPECIAL ORDER

The malware will get the command line of this launch process and will check if it has more than one argument (the first argument is always in C/C++) with the functions “GetCommandLineW”, to get the full command line with arguments if it exists, and “CommandLineToArgvW” to get the arguments if they exist.

If there is more than one argument the malware will avoid the next procedure. To keep the normal flow in the technical details section we will put what happens if only one argument exists. In this case the malware will try to make a Windows Event with the name of the formatted string with all hashes, as explained earlier (in our example case above, 78ef216f-91fffe45-56ef3218-f843256f-e35d68fe).

After trying to create the event the malware will check the last error with the function “GetLastError” and compare with ERROR_ALREADY_EXISTS (0xB7). If the event already exists the malware will check a counter with the value at 0x8000 (32768) and, if is not this value, it will increase the counter by one and try again to make the event, check the last error, and so on, until it can finally make the event, reach the counter value, or it reaches the maximum value in the counter (64233). If the event cannot be created the malware will get the pseudohandle to its own process with the function “GetCurrentProcess” and terminate it with the function “TerminateProcess” with the exit code 0x29A.

FIGURE 9. CREATE EVENT LOOP AFTER CHECKING THERE IS ONLY ONE ARGUMENT IN THE COMMAND LINE

This is done for several reasons:

  • The event is created to avoid relaunching another instance of the malware at the same time.
  • The check of the counter is made if another instance of the malware is launched, to wait for the previous one to finish before continuing the process (this avoids some issues with the malware checking for crypted files).
  • The check of the argument, as we will explain later, can be used to avoid the event behavior so the malware will always try to encrypt files. It is one of the reasons why a vaccine against this malware is useless if the malware operator executes the malware with an argument as simple as “1”.

After this, the malware will try to access in raw mode all units connected to the victim machine in a physical way, preparing the string “\\.\PHYSICALDRIVE%d”. This string will be formatted with the function “wsprintfW”, starting with the first unit that is 0 to a maximum of 16 in a loop. After the format, the malware will use “CreateFileW” and check that it does not return the error “ERROR_INVALID_HANDLE” (that means the unit cannot be accessed or that it does not exist). If this error is returned it will increase the counter and format the string with the new value of the counter. If it can open the handle to the unit in raw mode it will send two commands using the function “DeviceIoControl”.

The commands are:

  • 0x7C0F4 -> IOCTL_DISK_SET_DISK_ATTRIBUTES with the attributes of: DISK_ATTRIBUTE_READ_ONLY and DISK_ATTRIBUTE_OFFLINE.
  • 0x70140 -> IOCTL_DISK_UPDATE_PROPERTIES that will be make the drive update its partition table. As the attributes are updated the malware can be accessed in sharing mode on the disk.

FIGURE 10. CONTROL THE PHYSICAL DISK TO HAVE ACCESS TO IT

The ransomware’s next action is checking the units that exist and can be accessed without any problem. This can be done in two ways, the first of which is using the functions “FindFirstVolumeA”, “FindNextVolumeA” and “FindVolumeClose”.

FIGURE 11. GET VOLUME LETTER AND INFORMATION TO CHECK IT EXISTS AND CAN BE ACCESSED

The first two functions return the volume and the special internal value associated with it. This information comes from Windows, so the malware needs to translate it to the logic unit letter associated to this volume. This is done with the function “GetVolumePathNamesForVolumeNameA” that will return the logic letter associated to the volume inspected.

With this letter the function “GetVolumeInformationA” is then used to get information of the volume if it exists and is enabled. If the volume does not exist or cannot be checked the function will fail and the volume ignored, and the process will move onto the next volume in the machine.

Another check is made using the function “GetLogicalDrives” that will return a structure and, by checking one byte, the malware will know if the unit exists or not.

After this, the malware will prepare the keys that later will be needed to encrypt the files. To make them it will get the crypto context with the function “CryptAquireContextW” that will generate random data with “CryptGenRandom” and prepare to permutate this value with the SHA-512 algorithm. These values are the key and nonce of the Salsa20 algorithm that will be used later to encrypt files.

FIGURE 12. AQUIRE CRYPTO CONTEXT AND GENERATE SOME DATA AND PREPARE WITH SHA-512

The malware continues decrypting some strings using two steps, one in a big function for the first layer and the other that is used later for the second layer and the final string of the service. The services stopped are:

 

vss
sql
memtas -> associated with MailEnable
mepocs -> associated with MailEnable
Sophos -> associated with Sophos Antivirus
Veeam -> associated with a program to make backups and save in the cloud
Backup -> associated with Asus WebStorage
Pulseway -> associated with remote control software for IT departments
Logme -> associated with remote control software
Logmein -> associated with a remote control software
Conectwise -> associated with a remote control software
Splastop -> associated with a remote control software
Mysql -> associated with a program of databases
Dfs -> associated with the Distribute File System (Microsoft)

 

Please note: The services list can change between samples.

After decrypting the strings, the malware accesses the SCManager with the function “OpenSCManagerA”. If it does not want access it will ignore all services and continue onto the next step.

If it can open a handle to it, it will get the status of the service with the function “EnumServicesStatusA” and if the service is stopped already will pass to the next one. The malware calls this function two times, firstly to get the correct size needed for this function, with the last error being checked with ¨GetLastError¨ against the value 0xEA (ERROR_MORE_DATA) (that means that the application needs more memory to fill all information than the function gives).

FIGURE 13. OPEN THE SERVICE MANAGER AND ENUMSERVICESTATUS

This memory is reserved and the function called again later, in this case to get the real status and, if not stopped, the malware will open the service with the function “OpenServiceA” and query the status of the service with the function “QueryServiceStatusEx”. If the service is not stopped, it will get all dependencies of the service with “EnumDependentServicesA” and finally it will control the service to stop it with the function “ControlService”.

FIGURE 14. OPEN THE SERVICES AND CONTROL THEM

After this, the malware decrypts a list of the processes that it will try terminating if it finds them in the infected machine. For this decryption, the malware uses a string that converts into an integer and uses this integer as a critical value to decrypt the list.

For this task, the malware will create a snapshot of all processes in the system per this blacklist:

sql
mysql
veeam
oracle
ocssd
dbsnmp
synctime
agntsvc
isqlpussvc
xfssvccon
mydesktopqos
ocomm
dbeng50
sqbcoreservice
excel
infopath
msaccess
mspub
onenote
outlook
powerpnt
steam
thebat
thunderbird
visio
wordpad
winword
EduLink2SIMS
bengine
benetns
beserver
pvlsvr
beremote
VxLockdownServer
postgres
fdhost
WSSADMIN
wsstracing
OWSTIMER
dfssvc.exe
swc_service.exe
sophos
SAVAdminService
SavService.exe

 

Please note: The processes list can change between samples.

After making the snapshot it will enumerate all processes with the functions “Process32FirstW” and “Process32NextW” and for each process found will call the function “WideCharToMultyByte” to get the size needed to convert the name of the process returned in Unicode into Ascii. Later it reserves memory for the name and calls the same function to make the string conversion.

FIGURE 15. GET ALL SYSTEM PROCESSES

If the malware, after comparison with the function “StrStrIA”, detects some of the blacklisted processes it will open the process with the function “OpenProcess” and terminate it with the function “TerminateProcess” and with the exit  code of 0x29A.

FIGURE 16. OPEN THE PROCESS AND TERMINATE IT IF IT IS BLACKLISTED

The malware will check for all processes in the blacklist, using part of the string rather than the exact name. Not using the extension allows for greater obfuscation but carries the risk that some processes could be closed by accident if they share that string.

After this the malware will check if the operating system is 64-bit or not with the function “GetNativeSystemInfo” against the value 9 (that means that the OS is 64-bit).

If the operating system is 64-bit it will get, using “LoadLibraryW” and “GetProcAddress”, the function “Woe64EnableWow64FsRedirection” to remove the redirection that by default is found in 64-bit operating systems. This call is done in a dynamic way, but the malware does not check that the function was retrieved with success; usually it will be, but it is not 100% certain and a crash calling a null pointer could ensue.

FIGURE 17. CHECK THE OPERATING SYSTEM AND DISABLE REDIRECTION IF NEEDED

After this, the malware will prepare a string in Unicode embedded in the code with the string “wmic.exe shadowcopy delete” and will call it with the function “CreateProcessW”. After the call it will wait for up to an infinite amount of time using the function “WaitForSingleObject” so that the “wmic.exe” process can finish, irrespective of the size and number of shadow volumes, available machine resources, etc.

Of course, the malware will also use the typical program of “vssadmin” to delete the shadow volumes with the command “vssadmin delete shadows /all /quiet”, as well as with the function “CreateProcessW”. After that it will wait again with “WaitForSingleObject” for the end of the new process.

When it finishes, the malware will check again if the operating system is 64-bit and, if it is, will use “LoadLibraryW” and “GetProcAddress” to get the function “Wo64EnableWow64FsRedirection” to leave the system as before with the redirection. Again, the malware does not check that the function is resolved with success and calls it directly in a dynamic way.

FIGURE 18. DESTROY THE SHADOW VOLUMES AND RE-ENABLE THE REDIRECTION

While it seems like a mistake to destroy the shadow volumes again, it is not, as RagnarLocker has support for Windows XP and the WMIC classes do not exist in that operating system, hence the need to use the old program “vssadmin” that exists in both new and old operating systems.

The malware continues with the decryption of one PEM block encoded in base64 and the ransom note is prepared for the target in memory.

FIGURE 19. DECRYPTION OF THE PEM BLOCK AND THE RANSOM NOTE

An example of the ransom note, with confidential information removed, can be seen below:

FIGURE 20. EXAMPLE REDACTED RANSOM NOTE

After preparing both things the malware decodes the PEM block from the base64 as an object, getting a key that will be used to protect the keys used in the crypto process (of course this procedure may change in future samples as the malware evolves) of the RSA algorithm. It is important to note here that this RSA key changes per sample.

FIGURE 21. DECODE FROM BASE64 AND DECODE THE OBJECT AND IMPORT IT TO USE LATER

With this key it will encrypt the two random keys previously generated to protect them in memory. After that, the crypto will release the memory.

Later, it will get the name of the infected machine again, get the size of the name and will calculate the custom hash with the same algorithm as before.

FIGURE 22. CRYPT THE PREVIOUSLY GENERATED VALUES AND GET THE COMPUTER NAME

With this hash it will prepare a string with this structure:

  • RGNR_
  • hash from the name of the victim machine
  • the extension .txt
  • a backslash character at the start of the string

It is done with the function “lstrcatW”.

FIGURE 23. CREATION OF THE RANSOM NOTE NAME

With this string it will get the folder of “My Documents” for all users with the function “SHGetSpecialFolderPathW” (this function, based on the operating system, will get different paths for the documents). This string with the path of the folders will join with the string of the ransom note name and later make the final path to create the file.

FIGURE 24. GET THE DOCUMENTS FOLDER TO LATER WRITE THE RANSOM NOTE

After this it will encode in base64 the critical information to decrypt the files with the function “CryptBinaryToStringA”. The malware uses the function the first time to get the size needed and reserve memory and then uses it again to encode the data. After encoding the data, it creates the ransom note file in the documents path with the string previously joined with the path with the function “CreateFileW” and will write the contents of the ransom note that has been prepared in memory. Later, it will format a special string with some hardcoded characters with “—RAGNAR SECRET—” as a start of block and end of block and, between, will format the encode string in base64 and write in the ransom note.

FIGURE 25. CREATION OF THE RANSOM NOTE AND PUT THE RAGNAR SECRET AT THE END OF IT

Later, the malware will create a new string with the strings:

  • .ragnar_
  • hash of the name of the victim machine

This string will be used later as the new extension in the crypted files. After this the malware will enumerate again the logic units of the system with the function “GetLogicalDrivesW” and, to check if the unit is correct, will use the function “GetVolumeInformationW” and check the type of the unit and avoid the type of CD-ROM. For each logic unit it will enumerate all files and folders and will start the crypto process.

FIGURE 26. GET ALL LOGIC UNITS AND CHECK THEM

Before starting the crypto process, the malware will try to write the ransom note in the root of each unit that is found as a target.

The malware will ignore folders with these names:

Windows
Windows.old
Internet Explorer
Google
Opera
Opera Software
Mozilla
Mozilla Firefox
$Recycle.Bin
ProgramData
All Users

 

The ransom note will be written in all folders that are affected and, as with other ransomware, it will use the functions “FindFirstFileW” and “FindNextFileW” to enumerate all contents in each folder.

FIGURE 27. CHECK OF THE BLACKLISTED FOLDER NAMES

RagnarLocker also avoids crypting certain files:

autorun.inf
boot.ini
bootfont.bin
bootsect.bak
bootmgr
botmgr.efi
bootmgfw.efi
desktop.ini
iconcache.db
ntldr
ntuser.dat
ntuser.dat.log
ntuser.ini
thumbs.db
RGNR_<hash>.txt

 

 

FIGURE 28. CHECK OF BLACKLISTED FILE NAMES

If a file has one of these names it will be ignored and, if it has another name, the malware will avoid any file that has these extensions:

.db
.sys
.dll
.lnk
.msi
.drv
.exe

 

 

FIGURE 29. CHECK OF BLACKLISTED EXTENSIONS

These checks are in place to prevent the ransomware from destroying the operating system as the victim needs to have access to the machine to pay the ransom.

For each file that passes all controls a thread will be created that will encrypt it. After creating all threads, the malware will wait for up to an infinite amount of time with the function “WaitForMultipleObjects”.

In the crypto process, in the threads, the malware will check if the file has the mark “_RAGNAR_” at the end with the function “SetFilePointerEx” and by reading 9 bytes and checking if they are this string. If it has this mark the file will be ignored in the crypto process and will be renamed again (with an extension name based on the current machine name).

FIGURE 30. CHECK OF THE MARK OF CRYPTO IN THE FILE

In other cases the malware will encrypt the file and at the end of it will write the block crypted of the key, used in a block of 256 bytes, and the nonce used in another block of 256 bytes and, finally, the mark “_RAGNAR_”, along with one byte as NULL to end the string (that makes 9 bytes). The key and nonce used in the Salsa20 algorithm are encrypted by the RSA public key embedded in the malware. This ensures only the malware developers can have the RSA private key that belongs to the public key used to decrypt the key and nonce and, thus, decrypt the files in the system.

Before writing this information, the malware will use the function “LockFile” and, when the process of writing the function is finished, “UnlockFile” to release the file already crypted. This is done to prevent the file being changed or deleted during the encryption process.

FIGURE 31. WRITE THE NEW CONTENTS AT THE END OF THE FILE

After the crypto, or if the file is already crypted, the malware will change the extension to a new one, such as “.ragnar_45EF5632”.

FIGURE 32. CHANGE OF THE EXTENSION OF THE CRYPTED FILE

After all threads of crypto, the malware tries to get the session of the Terminal Services or the session of the user logged in the local machine with the function “WTSGetActiveConsoleSessionId”. With this session it gets the current process of the malware with the function “GetCurrentProcess” and the token of this process with the function “OpenProcessToken”. With the session that was got previously it tries to duplicate the token with the function “DuplicateTokenEx” and sets this token with the function “SetTokenInformation”. After this it will get the system directory with the function “GetSystemDirectoryW” and joins to this path the string “\notepad.exe”.

FIGURE 33. GET THE SESSION OF THE LOCAL USER OR TERMINAL SERVICES AND MANAGE THE TOKENS

With this prepared, the malware executes Notepad and, as an argument, the ransom note to show to the user what happened in the machine. The function used in this case is “CreateProcessAsUserW” to impersonate the user that had the session previously. Of course, this function is called with the desktop as “WinSta0\Default”.

FIGURE 34. CREATE A PROCESS OF THE NOTEPAD TO SHOW THE RANSOM NOTE

After this the malware finishes itself with the function “ExitProcess” and a code of exit of 0.

VACCINE

RagnarLocker can have a vaccine if a program is made that can make the event, as explained in the technical part of this blog. If this event exists, the malware does not make anything in the system, but this type of vaccine is not likely to offer a long-term solution for several reasons:

  • The way that the event is done, the malware developers can change the algorithm, or the order of the name of the event, or make a mutex instead of an event and the vaccine will stop working.
  • The algorithm has a hardcoded value. If this value is changed the final hash will be different and the vaccine becomes useless.
  • The malware is developed in such a way that if it has at least two arguments the event is not created so, if the operators want to execute with safety, they need only to execute with an argument, for example “<malware.exe> 1”.
  • The malware may evolve over time so the vaccine can be very fragile and limited.

For these reasons we think that a vaccine using this system is not helpful in the longer-term.

CONCLUSION

RagnarLocker is a simple ransomware, much like others that exist in the criminal market. Due to its small size, its operator’s aggressive behavior and the knowledge they seem to have that allows them to enter the networks of enterprises, as well as the threat to leak information if the ransom is not paid, RagnarLocker could potentially become a big threat in the future. Time will tell if RagnarLocker becomes a serious threat or disappears against a backdrop of other ransomware with more resources. The code is medium in quality.

COVERAGE

McAfee can protect against this threat in all its products, including personal antivirus, endpoint and gateway.

The names that it can have are:

  • Ransom-ragnar

Also, learn how Enhanced Remediation, a new capability in ENS 10.7, can automatically rollback changes made by processes that exhibit malicious behavior.

MITRE ATT&CK COVERAGE

  • Command and Control : Standard Application Layer Protocol
  • Defense Evasion : Disabling Security Tools
  • Discovery : Security Software Discovery
  • Discovery : Software Discovery
  • Discovery : System Information Discovery
  • Discovery : System Service Discovery
  • Discovery : System Time Discovery
  • Discovery : Query registry
  • Execution : Command-Line Interface
  • Execution : Execution through API
  • Exfiltration : Data Encrypted
  • Impact : Data Encrypted for Impact
  • Impact : Service Stop

YARA RULES

rule RagnarLocker

{

    /*

      This YARA rule detects the ransomware RagnarLocker in memory or unpacked in disk for the sample with hash SHA1 97f45184770693a91054075f8a45290d4d1fc06f and perhaps other samples

    */

    meta:

        author      = “McAfee ATR Team”

        description = “Rule to detect unpacked sample of RagnarLocker”

        version     = “1.0”

    strings:

        $a = { 42 81 F1 3C FF 01 AB 03 F1 8B C6 C1 C0 0D 2B F0 3B D7 }

    condition:

        $a

}

 

import “pe”

 

rule ragnarlocker_ransomware

{

   meta:

  

      description = “Rule to detect RagnarLocker samples”

      author = “Christiaan Beek | Marc Rivero | McAfee ATR Team”

      reference = “https://www.bleepingcomputer.com/news/security/ragnar-locker-ransomware-targets-msp-enterprise-support-tools/”

      date = “2020-04-15”

      hash1 = “63096f288f49b25d50f4aea52dc1fc00871b3927fa2a81fa0b0d752b261a3059”

      hash2 = “9bdd7f965d1c67396afb0a84c78b4d12118ff377db7efdca4a1340933120f376”

      hash3 = “ec35c76ad2c8192f09c02eca1f263b406163470ca8438d054db7adcf5bfc0597”

      hash4 = “9706a97ffa43a0258571def8912dc2b8bf1ee207676052ad1b9c16ca9953fc2c”

     

   strings:

  

      //—RAGNAR SECRET—

      $s1 = {2D 2D 2D 52 41 47 4E 41 52 20 53 45 43 52 45 54 2D 2D 2D}

      $s2 = { 66 ?? ?? ?? ?? ?? ?? 66 ?? ?? ?? B8 ?? ?? ?? ?? 0F 44 }

      $s3 = { 5? 8B ?? 5? 5? 8B ?? ?? 8B ?? 85 ?? 0F 84 }

      $s4 = { FF 1? ?? ?? ?? ?? 3D ?? ?? ?? ?? 0F 85 }

      $s5 = { 8D ?? ?? ?? ?? ?? 5? FF 7? ?? E8 ?? ?? ?? ?? 85 ?? 0F 85 }

     

      $op1 = { 0f 11 85 70 ff ff ff 8b b5 74 ff ff ff 0f 10 41 }

     

      $p0 = { 72 eb fe ff 55 8b ec 81 ec 00 01 00 00 53 56 57 }

      $p1 = { 60 be 00 00 41 00 8d be 00 10 ff ff 57 eb 0b 90 }

     

      $bp0 = { e8 b7 d2 ff ff ff b6 84 }

      $bp1 = { c7 85 7c ff ff ff 24 d2 00 00 8b 8d 7c ff ff ff }

      $bp2 = { 8d 85 7c ff ff ff 89 85 64 ff ff ff 8d 4d 84 89 }

     

   condition:

  

     uint16(0) == 0x5a4d and

     filesize < 100KB and

     (4 of ($s*) and $op1) or

     all of ($p*) and pe.imphash() == “9f611945f0fe0109fe728f39aad47024” or

     all of ($bp*) and pe.imphash() == “489a2424d7a14a26bfcfb006de3cd226”

}

 

IOCs

SHA256 7af61ce420051640c50b0e73e718dd8c55dddfcb58917a3bead9d3ece2f3e929
SHA256 c2bd70495630ed8279de0713a010e5e55f3da29323b59ef71401b12942ba52f6
SHA256 dd5d4cf9422b6e4514d49a3ec542cffb682be8a24079010cda689afbb44ac0f4
SHA256 63096f288f49b25d50f4aea52dc1fc00871b3927fa2a81fa0b0d752b261a3059
SHA256 b670441066ff868d06c682e5167b9dbc85b5323f3acfbbc044cabc0e5a594186
SHA256 68eb2d2d7866775d6bf106a914281491d23769a9eda88fc078328150b8432bb3
SHA256 1bf68d3d1b89e4f225c947442dc71a4793a3100465c95ae85ce6f7d987100ee1
SHA256 30dcc7a8ae98e52ee5547379048ca1fc90925e09a2a81c055021ba225c1d064c

 

USING MVISION EDR TO DETECT RAGNARLOCKER

With thanks to Mo Cashman and Filippo Sitzia

We downloaded a RagnarLocker sample from Virus Total to test detection capability by MVISION Endpoint Detection and Response (EDR). We tested first with the original sample which was known to most detection engines by this time. We then changed file hashes to test detection with an unknown sample. In both cases, MVISION EDR identified the suspicious behaviors and raised alerts. The original sample was detected as a HIGH Risk because the file had a known malicious reputation in McAfee Global Threat Intelligence which is integrated with MVISION EDR. The unknown samples were detected as Medium Risk and most likely would have triggered further inspection by a security analyst.

Sample VT submission

2020-05-30 13:30:55, File size: 48.50 KB, File type Win32 EXE, File name: omniga.exe, VT detections: 51/73

Test Environment

OS Win10, ENS 10.7 Threat Protection off, Adaptive Threat Protection off, MVISION EDR

Execution with original HASH – 3bc8ce79ee7043c9ad70698e3fc2013806244dc5112c8c8d465e96757b57b1e1

To further test MVISION EDR effectiveness, we modified the hash file slightly:

Execution with HASH changed – 63F5B6ED99C559341CF1AD081BAF55B4EACAD8E46D056764531BD316BF3C3EE3

Alerting Results for both samples

The post RagnarLocker Ransomware Threatens to Release Confidential Information appeared first on McAfee Blogs.

OneDrive Phishing Awareness

8 June 2020 at 16:37

There are number of ways scammers use to target personal information and, currently, one example is, they are taking advantage of the fear around the virus pandemic, sending phishing and scam emails to Microsoft OneDrive users, trying to profit from Coronavirus/COVID-19. They will pretend to be emailing from government, consulting, or charitable organizations to steal victim’s OneDrive details. OneDrive scammers will steal sensitive account information like usernames and passwords.  We would like to educate McAfee users and the public about the potential risks with these scams.

Nefarious Groups Attempt to Harvest Users’ Credentials

Below we will take you through three examples of this kind of attack, coming from a government organization, consulting firm and a charitable organization hosted in OneDrive to make them appear more genuine to users. As the screenshot below illustrates, the goal is to steal the user’s OneDrive credentials.

Fake Government Email Baits Victims

Scammers pretend to be from government offices and deliver documents that contain the latest live questionnaire regarding COVID-19. Remember: governments do not generally email the masses, sending unrequested documents, so a user could verify by examining the sender email address and location in the email headers and could visit the legitimate government site to see if there is COVID-19 information there instead.

When the folder in the above image is clicked on, it redirects to the screenshot shown below.

A warning saying “Hmm… looks like this file doesn’t have a preview we can show you” baits the visitor into clicking on the Open button. When clicked, it takes them to the below OneDrive screenshot prompting them to enter their personal information.

Notice that the link points users to a vulnerable WordPress site that contains a credential phishing landing page. A user should be aware that a legitimate OneDrive login page will never be hosted on a non-Microsoft domain. This should be a red flag to the user that this may be a scam or phishing attack.

 

As intended by the scammers, the user cannot access the OneDrive document to view the updated government questionnaire and, instead, will receive an error message to try again later.

By this stage, the scammers would have already stolen the user’s OneDrive personal information.

Fake Consulting Firm Attempts to Trick Users with Secured Document

Scammers pretend to be a consulting firm to share a secured document with the customer regarding the COVID-19 pandemic. Accepting an email document from a random and unsolicited consulting firm should be regarded as suspicious.

 

 

If a recipient clicks on the Download PDF link, it will take them to the page shown above where they are prompted to login. If they do so, it brings them to the below Microsoft login page where they enter their email address and password.

After attempting to sign in, the victim will be presented with an error message, as seen in the below screenshot.

When they enter their OneDrive information they will receive an error message saying, “Sorry, but we’re having trouble signing you in”. However, by this point, the scammers have already stolen the user’s OneDrive information.

Fake Charitable Organization Tries to Trick Volunteers

Some emails appear like charitable organizations looking for volunteers to help the community.

 

If someone clicks on the open PDF link, it will take them to the below OneDrive login page.

Scammers are trying to harvest company and individual OneDrive credentials by pretending to appear as a non-profit organization looking for volunteers.

 

The user is then presented with a login screen requesting their credentials.

However, they should notice the URL hosting the OneDrive login page is not from a Microsoft domain and should be regarded as suspicious.

Advice to Consumers

Consumers should be aware of scammers trying to harvest OneDrive details and should follow these best practices: –

  • Be careful of any charity or businesses requesting their OneDrive user information. Stick with organizations known to be reputable.
  • Never share financial or personal information over the phone, via email or with untrusted sites.
  • Remember that legitimate organizations will almost never send an email asking for personal information.
  • Never click on suspicious links or download attachments from unknown sources.
  • Never log in to a web page reached through a link from an email.
  • Remember email addresses can be spoofed so if a message looks suspicious, contact the sender via a known telephone number taken from their official website.

Advice to Organizations

  • Organizations should activate multi-factor authentication to prevent stolen credentials from been used to access OneDrive or Office 365 accounts.
  • Ensure all employees are aware of the threat posed by OneDrive and Office 365 phishing scams and consider security awareness training where appropriate.

 

If you find suspected scam sites, please submit them to McAfee for review at https://trustedsource.org as well as reporting them to your local law enforcement.

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How To Use McAfee ATP to Protect Against Emotet, LemonDuck and PowerMiner

19 May 2020 at 16:30

Introduction

This blog describes how McAfee ATP (Adaptive Threat Protection) rules are used within McAfee Endpoint Security products. It will help you understand how ATP Rules work and how you can utilize them to prevent infections from prevalent malware families such as Emotet, LemonDuck and PowerMiner. Please read through the recommendation section to effectively utilize rules in your environment.

ATP rules are a form of Attack Surface reduction technology which detects suspicious use of OS features and applications. These rules target behaviors which are often abused by malware authors. There can be cases where legitimate applications utilize the same behavior and hence rules need to be configured based on the environment.

ATP rules within McAfee Endpoint Security (ENS) 10.5.3 and above have already detected over a million pieces of malware since the start of 2020. This blog will show you how to enable ATP rules and explains why they should be enabled by highlighting some of the malware we detect with them. We’ll also show you how to maximize detection capabilities by tweaking some specific settings.

First, let’s start with an overview. We release ATP rules in three types: Evaluate, DefaultOn and HighOn.

Evaluate rules are tested in the field by McAfee to determine if they are robust enough to detect malicious activity while not producing false positives. Once a rule has been in evaluate mode for a period of time, McAfee researchers will analyze its performance and either make modifications or promote it to DefaultOn or HighOn. ENS ATP customers connected to McAfee ePolicy Orchestrator (ePO) can manually change Evaluate rules to Enabled mode.

DefaultOn rules are created when McAfee has high confidence that no legitimate applications will be impacted. These rules are then enabled by default in all McAfee Endpoint Security rule groups.

HighOn rules detect behavior that is known to be malicious but may have some overlap with non-malicious applications. These rules are set to Observe mode for systems in the “Balanced” rule group, but act as DefaultOn for systems in the “Security” rule group. Later in this blog, we cover how to change the rule group in Endpoint Security products to enable HighOn rules.

How to enable ATP rules in ENS 10.5.3 and above

By default, many ATP rules are set to Observe mode. To enable these rules in an active-blocking mode, login to the ePO Console and go to Menu->Configuration->Server Settings.

 

Figure 1. Rules in the Balanced rule group.

Select Adaptive Threat Protection and select the required rule group (Productivity, Balanced, or Security).

As seen in Figure 1, Rule 329 is in Observe mode in the Balanced rule group and, in Figure 2 below, you can see it is Enabled by default in Security rule group.

Note: As mentioned previously, we analyze rules from time to time and make modifications so you may have different settings in your environment, depending upon the content version.

 

Figure 2. Rules in Security rule group.

To enable a rule click on Edit below the rules and Select the rule you would like to change, then select the desired state – Disabled, Enabled, or Observe. Figure 3. shows how we can change the state of Rule 256 which helps in detecting Emotet and Trickbot downloaders.

 

Figure 3. Changing the Rule State.

Click on Save and the rule should be enabled on the clients within a few minutes. Here you see that Rule 256 blocks malicious file JTI/Suspect.131328 by default.

Figure 4. Evaluate Rule blocking after Enabling.

Change the assigned rule group to use HighOn rules in ENS 10.5.3 and above

In this section, we will step through how you can change the rule group to “Security” which will enable all the HighOn rules in block mode by default. We recommend you check the logs to see if the HighOn rules have detected clean activity within your environments before changing to this rule group.

To change the rule group, login to the ePO console and go to Menu->Systems->System Tree

Figure 5. Selecting the group of systems to modify Policies for ENS.

Select a group and go to the Assigned Policies tab. Select ‘Endpoint Security Adaptive Threat Protection’ from the product dropdown.

Figure 6. Selecting policies to modify the assigned rule group.

Click on ‘My Default’ policy under the ‘Options’ category.

 

Figure 7. Changing the rule group to Security.

Scroll down to Rule Assignment. From the Rule Assignment drop-down list, select Security and click Save. This will update all the clients with ‘My Default’ policy to the Security rule group.

Enable HighOn rules in MVISION Endpoint  

To enable HighOn rules, MVISION Endpoint policy needs to be set to ‘High Protection’ if it is not already set by default. Follow these steps:

Login to the ePO console and go to Menu->Systems->System Tree

Figure 8. Selecting the group of systems to modify policies for MVISION Endpoint

Select a group and go to the Assigned Policies tab. Select ‘MVISION Endpoint’ from the product dropdown.

Figure 9. Selecting the policies to change the Protection mode.

Click on ‘Edit Assignment’ under General Category.

Figure 10. Changing MVISION Endpoint to High Protection.

Change ‘Inherit from’ to ‘Break Inheritance and assign the policy and settings below’. Also, change the ‘Assigned policy’ to ‘High Protection’ from the dropdown list and click on ‘Save’. This will enable all the HighOn rules.

ATP Rules in the Wild

This section highlights three prevalent threats which ATP rules detect. We highlight one rule for each DefaultOn/HighOn/Evaluate to demonstrate the importance of monitoring rule updates and enabling more aggressive rules if they are suitable for your environment.

PowerMiner (DefaultOn example)

The PowerMiner malware is a cryptocurrency malware that has been prevalent since 2019. We have discussed this malware before in a previous blog on AMSI detection. The purpose of PowerMiner is to infect as many machines as possible to mine Monero currency. The initial infection vector is via phishing emails which contain a batch file. Once run, this batch file will execute a malicious PowerShell script that will then begin the infection process.

ATP DefaultOn Rule 263 “Detect processes accessing suspicious URLs” and Rule 262 “Identify suspicious command parameter execution for Security rule group assignments” blocks this threat once PowerShell is executed by the Dropper.bat and it attempts to download the malicious PS1 file.

This is shown by the red cross in the flow chart above. As mentioned in the AMSI blog, this threat is also covered by our AMSI signatures but as we do with several threats, we have different forms of detection in case the malware authors modify their code to attempt to bypass one of them.

The IP Map below shows the detections of this threat between October 2019 and January 2020 by the ATP Rules mentioned above.

LemonDuck (HighOn example)

LemonDuck, like PowerMiner, is a coin mining malware. It spreads via various methods such as the Eternal Blue exploit and Mimikatz. Once a machine has been infected, LemonDuck will create several scheduled tasks to download various components which include the coin mining functionality. The flow chart below shows the Lemon Duck infection process:

 

ATP HighOn rule 329 “Identify and block suspicious usage of Scheduled Tasks in high change systems” blocks LemonDuck at the schedule task creation stage. Again, like PowerMiner, McAfee also has an AMSI signature which detects this threat as LemonDuck!<partial_hash>.

The IP Map below shows the detections of this threat between October 2019 and January 2020 by the ATP Rule mentioned above.

Emotet Downloader (Evaluate example)

Emotet is a Trojan which is responsible for downloading and executing several high-profile malwares including Trickbot, which is turn has been known to download and execute the Ryuk ransomware. Emotet is usually downloaded and executed on the victim’s machine by malicious documents which are sent out via email spam. The malicious document will use PowerShell to download the Emotet executable and execute it. The flow is shown below:

 

McAfee ATP rule 256 ‘Detect use of long -encoded command PowerShell’ and rule 264 ‘Inspect EncodedCommand Powershell’ will detect this behavior if enabled. This is not enabled by default as this behavior can be legitimate, so we recommend checking the detections in Evaluate mode and, if no false positives occur, then turning it on. This rule will also block other malware which performs the same activity as Trickbot. The IP Map below shows the detections Rule 256 has had between October 2019 and January 2020. This will include all threats detected by this rule, not just Emotet.

Recommendations

By now you are likely asking yourself which rules you should turn on. Firstly, it should be noted that enabling ATP Rules will have no performance impact however, as highlighted in the first section, they can sometimes cause false positives.

From the collection of ATP rules, we recommend turning on the ‘Observe’ mode rules mentioned in this blog.

In addition to the rules mentioned for each threat, the following rules can be turned to ‘Enabled’ mode from the EPO console as we described. As mentioned, there is continuous evaluation of these rules by McAfee researchers which can result in rules moving to a different rule group or merging into other existing rules.

  • Rule 238– Identify abuse of common processes spawned from non-standard locations.
  • Protection from files being executed from suspicious locations which are often used by attackers.
  • Rule 309 – Block processes attempting to launch from Office applications.
    • Office documents are the main vectors used to deploy malware. This rule prevents Office applications from being abused to deliver malicious payloads.
  • Rule 312 – Prevent email applications, such as Outlook, from spawning script editors and dual use tool
    • Spam emails are common initial attack vectors being utilized by malware authors. This rule will help to detect suspicious use of email applications by preventing the launch of uncommon processes.
  • Rule 323 – Prevent mshta from being launched as a child process.
    • Related to MITRE technique T1170. Mshta.exe is a utility that executes Microsoft HTML Applications (HTA). Attackers can use mshta.exe to execute malicious .hta files and JavaScript or VBScript. This rule will help to detect the malicious use cases. You can read more about mshta here.

In general, we recommend looking through your ATP logs and checking to see if any ‘Observe’ mode rules are causing detections. If you find any rules that are not detecting legitimate use cases, we advise changing them to ‘Enabled’ mode.

We advise using ePO groups for a small number of machines and then monitor the changed environment for any false positives. If there are no false positives, you can then deploy the changes to a broader group.

KB Article KB82925 shows all the available ATP rules. You can also refer to the ATP Rules Release Notes which are updated when new rules are created, or existing ones are modified.

Conclusion

We hope that this blog has helped highlight how ATP rules protect your environment against a variety of threats and, by combining this technology with others like AMSI, we reinforce protection.

This blog continues a series which help showcase our technology, so we also recommend reading the following:

McAfee Protects against suspicious email attachments

McAfee AMSI integration protects against malicious scripts

Using Expert Rules in ENS to prevent malicious exploits

What Is Mshta, How Can It Be Used and How to Protect Against It

 

All testing was performed with the JTI Content Version 1134 and MVISION Endpoint Version 20.1.0.114 (in High Protection)

The post How To Use McAfee ATP to Protect Against Emotet, LemonDuck and PowerMiner appeared first on McAfee Blogs.

ENS 10.7 Rolls Back the Curtain on Ransomware

7 May 2020 at 04:02

Ransomware protection and incident response is a constant battle for IT, security engineers and analysts under normal circumstances, but with the number of people working from home during the COVID-19 pandemic that challenge reaches new heights. How do you ensure an equivalent level of adaptable malware protection on or off the corporate network? How do you enable remote services securely? How long will it take you to recover remote end user systems and data encrypted by ransomware?

As remote workers and IT engineers increasingly use Remote Desktop Protocol (RDP) to access internal resources, attackers are finding more weaknesses to exploit. Attackers are exploiting weak authentication or security controls and even resorting to buying RDP passwords in the underground markets. Exploiting these weaknesses can give an attacker admin access and an easy path to install ransomware or other types of malware, then find their way around the corporate network. To see some examples of how attackers are exploiting RDP weaknesses, check out additional blog posts from McAfee Advanced Threat Research (ATR)

In this blog, we will show how you can leverage Endpoint Security or ENS, McAfee’s Endpoint Protection Platform (EPP), led by some of the new capabilities in ENS 10.7 and MVISION Endpoint Detection and Response (EDR), to do just that.

ENS 10.7, with Threat Prevention, Firewall, Web Control and Adaptive Threat Protection modules backed up by Global Threat Intelligence (GTI) provides adaptable, defense in depth capability against the techniques used in targeted ransomware attacks. For more examples of these techniques, see McAfee ATR’s recent blog on LockBit. Pairing ENS 10.7 with MVISION EDR gives the SOC analysts a powerful toolset to quickly identify attempts to steal credentials and lateral move further into the network.

Finally, McAfee ePolicy Orchestrator (ePO) provides a central management console for endpoint security policy, event collection and reporting on your protected systems on or off the corporate network. Let’s explore some of the key defensive steps you can take to lower your risk against targeted ransomware.

Prevent Initial Access with Threat Prevention

The Endpoint Security Threat Prevention module contains several capabilities including signature scanning and exploit prevention through behavior blocking and reputation analysis, to prevent an attacker gaining access to the system. The first step is to ensure you have the minimum level of security in place. This includes following best practice for on-access and on-demand scanning policies, up to date DAT Files and Engine, and Exploit Prevention content, as well as Global Threat Intelligence access enabled. Targeted ransomware attacks may also leverage file-less exploit techniques which could bypass file-based signature scans and reputation checks. Exploit Prevention rules can be configured to either log or block PowerShell behavior.

However, PowerShell is a legitimate system administration tool and we recommend a period of observation and testing before setting any of these rules to block. For some best practice, you can review this guide as a starting point or check with support for the latest documents.

Restrict RDP as an Initial Attack Vector with Endpoint Security Firewall

If RDP is needed to access internal resources on a server or to troubleshoot a remote system, the best practice is to restrict access to the service using a firewall. This will prevent attackers from leveraging RDP as the initial access vector. ENS 10.7 contains a stateful firewall fully managed via McAfee ePolicy Orchestrator (ePO). You can create policies to restrict RDP access to a remote client to only authorized IP addresses, restrict outbound usage to prevent lateral movement by RDP or block access to that port altogether. Here is an example configuration to restrict inbound access to a remote system on RDP.

  1. Open your Firewall Rules policy and locate the default rule under Network Tools.

  1. If you are using a non-standard port for RDP adjust the local port for this rule appropriately.
  2. Modify the rule by adding authorized IP addresses as remote networks (these are the remote addresses authorized to connect to your endpoints).

  1. Save the changes and apply the policy to endpoints to restrict RDP access.

For additional security create an identical rule but set to block rather than allow, position it below the above rule, and remove the remote IP addresses (so that it applies to all RDP connections not matching the above rule).

  1. Set this rule as an intrusion so that it logs all denied events and forwards them to ePO.

Security analysts in the SOC can then monitor and report on unauthorized access attempts through ePO dashboards. The event logs are useful for early warning, trend analysis and for threat detection and response.

You can find more information on Endpoint Security firewall features here.

Prevent Access to Malicious Websites with Web Control

Attackers often leverage watering holes and spear phishing with links to malicious sites to gain initial access or further infiltrate the network. When a user is on the corporate network, they are often behind a Web Proxy like McAfee Web Gateway. However, many of your mobile clients are going direct to the internet and not through the corporate VPN. This creates more exposure to web-based threats. The Endpoint Security Web Control module monitors web searching and browsing activity on client computers and protects against threats on webpages and in file downloads.

You use McAfee ePO to deploy and manage Web Control on client systems. Settings control access to sites based on their safety rating, reputation from Global Threat Intelligence, the type of content they contain, and their URL or domain name. The configuration settings allow you to adjust sensitivity to be more or less restrictive based on your risk appetite.

If you are a McAfee Web Gateway or Web Gateway Cloud Service customer, you should use McAfee Client Proxy (MCP). MCP works with Web Control to route traffic to the right proxy and provide a defense in depth capability for web protection for users on or off the corporate network.

The above are just a few examples of using Endpoint Security Threat Prevention, Web Control and Firewall to restrict initial attack vectors. To learn more about Endpoint Security best practice to restrict initial entry vectors, visit here.

Let’s look at a few more important steps to protect systems against targeted ransomware.

Lockdown the Security Crown Jewels

If an attacker gets on the system through RDP stolen accounts or vulnerability, they may try to modify, delete or disable security software. In ePO, you should ensure that Self Protection is ON to prevent McAfee services and files on the endpoint or server system from being stopped or modified.

Ensure that ENS is configured to require a password for uninstallation.

 

Security analysts should be on high alert for any system that has Self Protection disabled. ePO contains a default query entitled Endpoint Security: Self Protection Compliance Status which can be used to populate a continuous monitoring dashboard or be packaged into a daily report.

Disrupt and Visualize Attacker Behavior with Adaptive Threat Protection (ATP)

ATP adds several more capabilities, such as machine-learning, threat intelligence, script-scanning and application behavior analysis, to disrupt targeted attack techniques including file-based or file-less attacks.

ATP identifies threats by observing suspicious behaviors and activities. When ATP determines that the context of an execution is malicious, it blocks the malicious activity, and if necessary, remediates (see Enhanced Remediation section below). How does this work? The Real Protect scanner inspects suspicious activities on client systems and uses machine-learning techniques to detect malicious patterns. The Real Protect scanner can scan a network-streamed script, determine if it is malicious, and if necessary, stop the script. Real Protect script scanning integrates with AMSI to protect against non-browser-based scripts, such as PowerShell, JavaScript, and VBScript.

For more information on how ATP remediates threats please review the product guide here.

One of the newest features of ENS 10.7 is the Story Graph. The Story Graph provides a visual representation of threat detections. Below is an example from a simulated file-less attack scenario where a Word document, delivered through spear-phishing, leverages a macro and PowerShell to provide command and control, then elevate privileges and perform lateral movement.

The visualization provides a timeline analysis and context around the event. It correctly captured the attack behavior including the communication to an external attacker IP address. With this visualization, an administrator or security analyst can quickly determine malicious behavior was stopped by ATP, preventing the follow-up activity intended by the attacker. The additional context, such as the originating process and a download IP address, can then be used for further investigations using other log sources, for example. It is important to note that in this example, if the Threat Prevention module as described above was set to block all PowerShell behavior, this attack would have been stopped earlier in the chain. Please read further to see what this attack scenario looks like in MVISION EDR.

For more information on how ATP protects against file-less attacks visit here.

Using a Word document and PowerShell is just one example of masquerading attacks in common files. For more examples of these techniques, see the ATR blog on LockBit ransomware.

ATP Brings Automatic File Recovery with Enhanced Remediation

If you have ever seen a ransom note, like the one from Wanna Decryptor below, you will know how big an issue it can be. It will cost you time, money and most likely lead to loss of data.

If this happens on a remote user system, it will lead to extended downtime, frustrated users and present significant challenges for recovery.

One of the new capabilities in ENS 10.7 is Enhanced Remediation. This feature monitors any process with an unknown reputation and backs up changes made by those processes. If the processes exhibit malicious behavior as determined by machine-learning analysis and reputation, enhanced remediation automatically rolls back those changes made to the system and documents to a previous state.

You can see how files impacted by ransomware can be restored through Enhanced Remediation in this video.

Enhanced Remediation requires that ATP is enabled and policies for Dynamic Application Containment are configured. Real Protect Dynamic scanning must also be enabled on the system. Real Protect Dynamic leverages machine learning in the cloud to identify suspicious behavior and is needed to determine a file reputation which is used to trigger an enhanced remediation action.

For information on how to configure ATP, please review the product guide here. For more best practices on tuning Dynamic Application Containment rules, please review the knowledge base article here.

Once policies are established, ensure that you enable “Enhanced Remediation” and “Monitor and remediate deleted and changed files”

If a file is convicted by Real Protect Dynamic and Enhanced Remediation is enabled with the settings above, then recovery happens automatically. The setting “Monitor and remediate deleted or changed files” must be enabled to ensure any files modified by the ransomware are restored to the previous state.

For more information on how Enhanced Remediation works, please review the product guide here.

Continuous Monitoring with ePO Protection Workspace

Now that you have protection controls in place with Threat Prevention and Adaptive Threat Protection, you can monitor using the Compliance Dashboard in ePO to ensure all managed clients stay up to date.

In addition, events triggered by ATP can be sent to ePO. SOC analysts should monitor these events and use the Story Graph as well for additional investigative capability. For more information on reporting and querying events in ePO, please review the product guide here.

Proactive Monitoring and Hunting with MVISION EDR

One of the first questions a threat hunter needs to answer when a new threat is discovered is “are we exposed?” For example, you may have a policy that already prohibits or restricts RDP but how do you know it is enforced on every endpoint? With MVISION EDR, you can perform a real time search across all managed systems to see what is happening right now. The screenshot below shows a Real-time Search to verify if RDP is enabled or disabled on a system. This provides a view into systems potentially at risk and can also be useful context as part of an investigation.

Real-time Search can also identify systems with active connections on RDP…

MVISION EDR also maintains a history of network connections inbound and outbound from the client. Performing an historical search for network traffic could identify systems that actively communicated on port 3389 to unauthorized addresses, potentially detecting attempts at exploitation.

For a security analyst, EDR providers several benefits to accelerate threat detection and response. For more information on those benefits please review the product guide here. In our simulated file-less attack scenario described above, the story graph revealed a PowerShell connection to an external IP address. Suppose an alert ePO administrator created a ticket for further investigation. A first step by the analyst might be a search for the network activity.

Real-time Search in EDR of that network activity looks like this…

An historical search for the same PowerShell activity in EDR now reveals the encoded commands used in the initial entry vector…

EDR also enables proactive monitoring by a security analyst. The Monitoring Dashboard helps the analyst in the SOC quickly triage suspicious behavior. In this case, the attack leveraged Word and PowerShell to gain access and raise privileges. The attack scenario triggered a number of high threats and provides a lot of context for the analyst to make a quick determination that an attack has been attempted, requiring further action…

Our research into targeted ransomware attacks reveals that if an attacker successfully exploits a client, their next actions involve privilege escalation and lateral movement (see our blog on LockBit). Again, you can use MVISION EDR to quickly detect these techniques.

The Alerting Dashboard in EDR will help you quickly identify attempts at privilege escalation and other attack techniques as defined by the MITRE ATT&CK framework.

Lateral movement is usually the next step and that can involve many different techniques. Again, the Alerting Dashboard identifies lateral movement techniques with details into the specific activity that triggered the alert.

Conclusion

Ransomware and RDP are a dangerous combination. Protecting your remote end users requires a good, secure baseline configuration of Endpoint Security with a Firewall and Self Protection enabled and access to adaptable capability such as Adaptive Threat Protection with Enhanced Remediation. The Enhanced Remediation feature is only available starting in version ENS 10.7, so if you are running older versions of ENS or even VSE (yikes), then it is time to upgrade.

However, stopping targeted ransomware from having an impact on the business requires more than prevention. Both ePO and EDR provide the capability for proactive detection, faster investigations and continuous hunting.

Finally, adaptability requires threat intelligence. McAfee Advanced Threat Researchers and Labs are actively monitoring the threat landscape and continuously updating McAfee Global Threat Intelligence systems. Make sure your Endpoint Security and other McAfee products are using GTI for the latest protection.

For more information on targeted ransomware attacks and techniques, see ATR Blog.

For more details about how to securing RDP access in general, you can refer to a previous McAfee blog.

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