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Before yesterdaySec Team Blog

Internal security recommendations survey

11 October 2021 at 13:11

During the first wave of Covid and most people locked up at home, I wanted to engage with my colleagues in various departments here at SCRT by having them answer a simple survey. The survey related to what actions they would recommend and prioritize in order to secure the information system of a random company, which had just received notification that a cyberattack was imminent.

The survey

Everybody was asked to provide up to 10 recommendations and my initial goal was to see whether there was a consensus between our different teams. For example, I wanted to make sure that our sales team would provide similar answers to our engineering teams.

In any case, I wanted to keep the answers as open as possible, which made it a little harder to parse the results, since some of my colleagues gave some very creative answers. One such example were the recommendations of writing a book on how to obtain a magical budget, followed by a sequel on how to spend that budget with SCRT. Needless to say, this was a bit of an outlier, but for other cases, I attempted to group similar answers into categories. For example, the two following recommendations “Install a good anti-virus solution on workstations” and “Setup EDR agents on all workstations and servers with machine learning capabilities such as Cortex XDR Pro” were eventually summarised as “EDR/AV”.

I had to make some choices as to what would be grouped together. I decided EDR and AV solutions could be considered as a similar recommendations, while I decided that “Updates” and “Vulnerability management” were going to remain separate. A number of answers were grouped into “Network isolation” which also explains some of the results I’ll give below.
After categorizing each one of the recommendations, I then attributed a weight from 1 to 10 to each of them depending on the priority given by the person.

Results

Without any further ado, here are the most frequently recommended actions (with their cumulated weight) out of the 33 colleagues who responded to my survey:

  1. Network isolation (173)
  2. Security patching (107)
  3. Configurations hardening (100)
  4. Limit external exposure (97)
  5. SIEM/SOC (95)
  6. Awareness training (95)
  7. Audit (89)
  8. Multi-factor authentication (87)
  9. Privileged access management (82)
  10. Backups (49)
  11. EDR/AV (45)
  12. LAPS (41)
  13. Robust password policy (40)
  14. DMZ (37)
  15. WAF (37)
    […]
  16. Contact SCRT 😉 (22 points)

If we ignore the weights and just count the number of times each recommendation is given, we obtain the following results.

  1. Network isolation (25)
  2. SIEM/SOC (22)
  3. Audit (22)
  4. Security patching (20)
  5. Configurations hardening (20)
  6. Awareness training (15)
  7. Privileged access management (14)
  8. Multi-factor authentication (14)
  9. Limit external exposure (11)
  10. EDR/AV (9)
  11. Robust password policy (8)
  12. LAPS (7)
  13. Backups (7)
  14. Bitlocker (6)
  15. Physical access (5)
    […]
  16. Contact SCRT 😉 (4)

Discussion

The differences are interesting to look at as they mean for example that most people recommended implementing a SIEM/SOC and performing an audit, but these were not considered as priorities.

I think it is important here to stress that when we mention “network isolation”, it goes beyond simple network segmentation. We are not talking about ensuring you have different VLANs for different types of systems, but actively enforcing appropriate firewalls between VLANs and within the same VLAN. It is this active firewalling which can prevent the exploitation of vulnerabilities in the first place and reduce the possibilities of lateral movement. While micro-segmentation and Zero Trust are valuable objectives, in the mean time, properly configuring the current firewalls has to be a priority.

When analysing the responses on a department level, it was interesting to see that our support team tends to recommend contacting SCRT and our analytics team recommends implementing a SIEM/SOC. Our pentesting team does not necessarily recommend performing an audit as a top priority, probably because we already anticipate what the findings are likely to be, which kind of skews the results. For our sales team though, performing an audit received the highest priority.

Wrapping things up

Based on the answers, I drew up a mindmap of actions that could be taken to improve the security of an information system. It contains more details than what is summarised in this blog post and the actions have been grouped by the following objectives:

  • Prevent the initial intrusion
  • Detect the intrusion
  • Limit its propagation
  • Protect/preserve sensitive data
  • Manage risk

There is already quite a bit of information in here, though there is even more which is still missing, but it does give an overview of the higher priority aspects, which can be worked on to generally improve the security posture of a company.

TPM sniffing

15 November 2021 at 13:37
TL;DR: we reproduced Denis Andzakovic’s proof-of-concept showing that it is possible to read and write data from a BitLocker-protected device (for instance, a stolen laptop) by sniffing the TPM key from the LCP bus. Authors: Thomas Dewaele & Julien Oberson Special thanks to Denis Andzakovic for his proof-of-concept and Joe Grand (@joegrand) for his hardware hacking … Continue reading TPM sniffing

SOCs real-life challenges & solutions

7 February 2022 at 11:10
Introduction As SCRT’s blue teamers, we often deal with Security Operations Centers (SOCs). Being able to interact with many different SOCs for our consultancy service gives us the possibility to understand the main challenges a SOC faces and how to solve them. This blog post results from a Master of Advanced studies’ thesis for Geneva’s … Continue reading SOCs real-life challenges & solutions

Apiculture 1 write-up

29 March 2022 at 19:25
The Apiculture challenges are dedicated to API attacks. It is basically a honey’s addict website: To solve the first challenge, we should pay attention to the call to the /api/products/ API: This endpoint provides information to the Angular front-end so that the page can be rendered in the browser… But it is impacted by an … Continue reading Apiculture 1 write-up

Apiculture 2 write-up

29 March 2022 at 20:13
The Apiculture challenges are dedicated to API attacks. The second level basically looks like a webpage dedicated to beehives: A quick look in the Developer Tools reveals a call to the /api/v4/products/ endpoint: This endpoint indeed permits to get the beehives JSON. It is also impacted by an Improper Data Filtering vulnerability since it contains … Continue reading Apiculture 2 write-up

GDBug write-up

29 March 2022 at 19:21
The GDBug file is an ELF binary: It simply requires a valid serial that we should identify: The strings do not reveal anything, besides a fake flag which is not accepted: Anyway, the binary doesn’t seem to have particular protections: There only seems to be a basic anti-debug: But old versions of GDB and Radare2 … Continue reading GDBug write-up

Splunk Boss Of The SOC (BOTS) @Insomni’hack

4 April 2022 at 09:28
It’s was a pleasure this year to meet you at the 2022 edition of our amazing security conference Insomni’hack ! With Splunk collaboration, we come back this year with “Splunk Boss Of The SOC” challenge. What is BOTS and his history Boss Of The SOC (BOTS) is a blue-team version of capture the flag competition. … Continue reading Splunk Boss Of The SOC (BOTS) @Insomni’hack

Automatically extracting static antivirus signatures

By: plowsec
5 April 2022 at 09:42
This blog post accompanies the talk we gave at Insomni’hack 2022. The source code as well as the slides can be found at: https://github.com/scrt/avdebugger Introduction What can we do when a tool that we use during pentest engagements becomes detected by antivirus software? For a long time, the answer was: use a packer. After a … Continue reading Automatically extracting static antivirus signatures

Statically encrypt strings in a binary with Keystone, LIEF and radare2/rizin

By: plowsec
11 April 2022 at 10:09
In our journey to try and make our payload fly under the radar of antivirus software, we wondered if there was a simple way to encrypt all the strings in a binary, without breaking anything. We did not find any satisfying solution in the literature, and the project looked like a fun coding exercise so … Continue reading Statically encrypt strings in a binary with Keystone, LIEF and radare2/rizin

Engineering antivirus evasion (Part III)

By: plowsec
19 April 2022 at 10:05
Previous blog posts addressed the issue of static artefacts that can easily be caught by security software, such as strings and API imports: This one provides an additional layer of obfuscation to target another kind of detection mechanism used to monitor a program’s activity, i.e userland hooks. As usual, source code was published at https://github.com/scrt/avcleaner … Continue reading Engineering antivirus evasion (Part III)

Getting Started With SplunkUI

3 January 2023 at 13:06
When developing new Splunk apps with a customised user interface, everything but SplunkUI is deprecated. Thus, it is only a matter of time before you need to jump from that building with faith. Most Splunk users are not web developers. Developing web UI is known to be a nightmare, that’s why they chose to be … Continue reading Getting Started With SplunkUI

Producing a POC for CVE-2022-42475 (Fortinet RCE)

14 March 2023 at 10:24
Late last year a new remote code execution vulnerability was discovered in Fortinet’s SSLVPN service. Given the relative lack of information surrounding it at the time, and the fact I’d have some uninterrupted research time due to a lengthy flight, I decided to attempt to produce a POC for the vulnerability. Background information I started … Continue reading Producing a POC for CVE-2022-42475 (Fortinet RCE)

Bypassing PPL in Userland (again)

17 March 2023 at 15:54
This post is a sequel to Bypassing LSA Protection in Userland and The End of PPLdump. Here, I will discuss how I was able to bypass the latest mitigation implemented by Microsoft and develop a new Userland exploit for injecting arbitrary code in a PPL with the highest signer type. The current state of PP(L)s … Continue reading Bypassing PPL in Userland (again)

Attacking Android Antivirus Applications

By: 2Dai
29 March 2023 at 12:43
Although the usefulness of security tools such as Antivirus, VPN and EDR is now indisputable in business circles, these solutions often need a lot of privileges and permissions to work properly, also making them an excellent target for an attacker. The presence of a bug in one of these types of solutions could allow a … Continue reading Attacking Android Antivirus Applications

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Insomni’hack 2023 – hex-filtrate writeup

1 April 2023 at 19:12
In this forensic challenge, a company has been compromised and their initial investigation led to a suspicious workstation. The CEO was very anxious about a potential exfiltration, and we were provided with a network dump of that workstation in the hope that we would be able to help him make some sweet dreams again. After … Continue reading Insomni’hack 2023 – hex-filtrate writeup

Insomni’hack 2023 CTF Teaser – DoH ! writeup

By: qlu
13 April 2023 at 14:26
For this 2023 edition, i chose to focus on the DoH (DNS Over Https) protocol because it has gained popularity for attackers as a command and control (C2) communication channel for hiding DNS traffic through HTTPS rather than using the traditional DNS tunneling. In this post, i will describe in details how to solve the … Continue reading Insomni’hack 2023 CTF Teaser – DoH ! writeup

Apache Solr 8.3.1 RCE from exposed administration interface

1 May 2023 at 07:41
Back in 2020, during an external pentest, I stumbled upon a visible Solr administration panel. With nothing else of interest, I focused on this specific application to test what was hidden underneath. The version of Apache Solr was 8.3.1 and running on Windows. Note that this pentest was performed in 2020, way before the discovery … Continue reading Apache Solr 8.3.1 RCE from exposed administration interface

CVE-2022-41099 – Analysis of a BitLocker Drive Encryption Bypass

14 August 2023 at 14:12
In November 2022, an advisory was published by Microsoft about a BitLocker bypass. This vulnerability caught my attention because the fix required a manual operation by users and system administrators, even after installing all the security updates. Couple this with the fact that the procedure was not well documented initially, and you have the perfect … Continue reading CVE-2022-41099 – Analysis of a BitLocker Drive Encryption Bypass

A Deep Dive into TPM-based BitLocker Drive Encryption

15 September 2023 at 15:14
When I investigated CVE-2022-41099, a BitLocker Drive Encryption bypass through the Windows Recovery Environment (WinRE), the fact that the latter was able to transparently access an encrypted drive without requiring the recovery password struck me. My initial thought was that there had to be a way to reproduce this behavior and obtain the master key … Continue reading A Deep Dive into TPM-based BitLocker Drive Encryption

Exploiting stale ADIDNS entries

25 September 2023 at 09:46
The correct IP address is sometimes all you need to exploit a remote target. Background I realise this article will not help me with my colleagues who believe I just happen to get lucky on every assessment I’m on. Nevertheless, during a recent internal pentest, our first objective was to attempt to bypass the Network … Continue reading Exploiting stale ADIDNS entries

Insomni’hack 2024 – Bash to the Future writeup

28 April 2024 at 20:41
The Challenge You have been contracted to help COPERNIC Inc spot the light on a potential compromise. It seems that one of their scientists has been spied through a 20 years old malware… And fortunately, Zeus was on your side since the 4 Gb snapshot was carried out at the best possible time to facilitate … Continue reading Insomni’hack 2024 – Bash to the Future writeup
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