SCRT Team Blog – Page 2 – Orange Cyberdefense Switzerland's technical blog

A Deep Dive into TPM-based BitLocker Drive Encryption

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 from the Recovery Environment (WinRE). The outcome of a generic BitLocker bypass was too tempting not to explore this idea…

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

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 recipe for disaster.

This is typically the kind of vulnerability you do not want to deal with when you are in charge of a large fleet of workstations and laptops. However, on the other side of things, hard to patch vulnerabilities such as this one usually offer the best opportunities for red teamers and the like. This is where my journey investigating this bug and learning more about TPM-based BitLocker Drive Encryption began.

Apache Solr 8.3.1 RCE from exposed administration interface

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.

Insomni’hack 2023 CTF Teaser – DoH ! writeup

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 challenge.

Insomni’hack 2023 – hex-filtrate writeup

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.

Attacking Android Antivirus Applications

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 malware to elevate its privileges and cause more damage to the organization.

Bypassing PPL in Userland (again)

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.

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

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.

Getting Started With SplunkUI

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.

Engineering antivirus evasion (Part III)

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.