Publications

Java deserialization tricks

19/03/2024 During a red team engagement, we faced Java applications exposed on the internet and affected by arbitrary deserialization from user-supplied data. After quickly identifying a well-known gadget chain, we noticed that a WAF was rejecting requests exploiting the vulnerability by detecting specific patterns of the serialized chain, and that an EDR caught our first exploit. Moreover, firewalls were strictly filtering outbound traffic, including DNS. This article will present a few tricks regarding the gadgets that were used to exploit the...

Arlo: I'm watching you

08/03/2024 The consumer-focused Pwn2Own competition returned in Toronto in 2023 with the "SOHO smashup" category, but also added cameras under a new "Surveillance Systems" category. While we already had success with the Wyze Cam v3 and Synology BC500 in this category, other targets were also looked at. Therefore, this blog post aims at bootstrapping vulnerability research on Arlo cameras.

Using Veeam metadata for efficient extraction of Backup artefacts (1/3)

08/02/2024 Veeam Backup & Replication is a widely-used software suite for creating and managing backups of virtual, physical and cloud machines. In a remote incident response, where efficient data access is key, Veeam metadata files can be used to list and search for Backup objects. This article explores the structure of Veeam metadata and how to use a Velociraptor artifact to restructure this data.

KrustyLoader - Rust malware linked to Ivanti ConnectSecure compromises

29/01/2024 On 10th January 2024, Ivanti disclosed two zero-day critical vulnerabilities affecting Connect Secure VPN product: CVE-2024-21887 and CVE-2023-46805 allowing unauthenticated remote code execution. Volexity and Mandiant published articles reporting how these vulnerabilities were actively exploited by a threat actor. On 18th January, Volexity published new observations including hashes of Rust payloads downloaded on compromised Ivanti Connect Secure instances. This article presents a malware analysis of these unidentified Rust payloads ...

Exploring Counter-Strike: Global Offensive Attack Surface

08/01/2024 Back in 2021, we studied the attack surface of Counter-Strike: Global Offensive as a side research project. We found and reported a relative heap out-of-bounds write vulnerability triggerable remotely, impacting code that is no longer present with the release of Counter-Strike 2. In fact, no patch was released in the meantime despite multiple follow-ups. We share today the details of this bug and our research about the attack surface and generic exploitation primitives.

Leveraging Binary Ninja IL to Reverse a Custom ISA: Cracking the “Pot of Gold” 37C3

05/01/2024 This article explores the process of reversing a custom instruction set architecture (ISA) of the Pot of Gold CTF challenge (37C3 CTF) using Binary Ninja Intermediate Language (IL) to decompile the challenge code. Next, it describes the exploitation part, first getting code execution in the emulator, then pivoting to a second process and ultimately exploiting the opcode emulation to retrieve the flag.

Writing a decent win32 keylogger [3/3]

21/12/2023 In this series of articles, we talk about the ins and out of how to build a keylogger for Windows that is able to support all keyboard layouts and reconstruct Unicode characters correctly regardless of the language (excluding those using input method editors). In the first part, after a brief introduction introducing the concepts of scan codes, virtual keys, characters and glyphs, we describe three different ways to capture keystrokes (GetKeyState, SetWindowsHookEx, GetRawInputData) and the differences between those techniques. In t...

Writing a decent win32 keylogger [2/3]

21/12/2023 In this series of articles, we talk about the ins and out of how to build a keylogger for Windows that is able to support all keyboard layouts and reconstruct Unicode characters correctly regardless of the language (excluding those using input method editors). In the first part, after a brief introduction introducing the concepts of scan codes, virtual keys, characters and glyphs, we describe three different ways to capture keystrokes (GetKeyState, SetWindowsHookEx, GetRawInputData) and the differences between those techniques. In t...

Writing a decent win32 keylogger [1/3]

21/12/2023 In this series of articles, we talk about the ins and out of how to build a keylogger for Windows that is able to support all keyboard layouts and reconstruct Unicode characters correctly regardless of the language (excluding those using input method editors). In the first part, after a brief introduction introducing the concepts of scan codes, virtual keys, characters and glyphs, we describe three different ways to capture keystrokes (GetKeyState, SetWindowsHookEx, GetRawInputData) and the differences between those techniques. In t...

Frinet: reverse-engineering made easier

18/12/2023 By combining Frida with an enhanced version of Tenet, Frinet facilitates the study of large programs, vulnerability research and root-cause analysis on iOS, Android, Linux, Windows, and most architectures.