Publications

Understanding and evading Microsoft Defender for Identity PKINIT detection

06/05/2024 A few months following our blogpost on Microsoft Defender for Identity, new alerts related to Active Directory Certificate Services were added. This article will focus on suspicious certificate usage alerts: the detection mechanism will be explained as well as how to avoid raising any alert. In addition, a PowerShell script will be released to perform Kerberos authentication via PKINIT with the Windows API, from a non domain-joined machine.

iOS: a journey in the USB networking stack

30/04/2024 In this article, we give a small journey inside the implementation of networking interfaces exposed by iOS when connected via USB. These are used for sharing a computer's connection with iPhone (tethering), sharing an iPhone's connection with a computer (reverse tethering) and since the latest versions of iOS, USB networking even carries RemoteXPC packets which seems to be the future common ground for all Apple based cross-device communications.

👻 Souls without bodies, phantom types shenanigans 👻

26/04/2024 In this article, we will present strange data types that only exist in the realm of types, called phantom types. We will also briefly introduce GADTs, and how to emulate some of their safety guarantees in languages where they are not available. This simple technique can go a long way towards making APIs safer and more expressive.

So I became a node: exploiting bootstrap tokens in Azure Kubernetes Service

23/04/2024 During one of our assessments, we managed to retrieve a Kubernetes bootstrap token from an AKS pod. It was a good opportunity to get a closer look at these tokens, how they work and how to exploit them. In this first blog post, we will describe the inner working of bootstrap tokens, the node authorization mode, signers and certificate controllers. Then we will show how to exploit a pod sharing the host network namespace in an AKS environment to leak such a token. The information provided in this blog post is based on Kubernetes v1.28 ...

OUned.py: exploiting hidden Organizational Units ACL attack vectors in Active Directory

19/04/2024 Exploitation of Organizational Units (OUs) ACLs received comparatively little attention when it comes to the security analysis of domain objects permissions in Active Directory environments. Yet, their successful exploitation could lead to the compromise of all OU child objects, and thus to high-impact privilege escalation scenarios. Building upon the work of Petros Koutroumpis, this article will present how an attack based on the manipulation of the gPLink attribute of Organizational Units could be exploitable through several common ...

Quantum readiness: Introduction to Modern Cryptography

18/04/2024 This article is the first of a series of articles regarding Post-Quantum Cryptography in 2024. It builds upon Synacktiv's 2021 article, "Is it post quantum time yet?", by presenting the evolutions that happened since then in the PQC world as well as various constructions that will be reused in the next articles. These articles will especially focus on giving the reader a good understanding of the attack surface one should consider when designing and implementing a PQC algorithm. This article considers that the concepts presented in o...

Entra ID Banned Password Lists: password spraying optimizations and defenses

17/04/2024 Banned Password Lists is a feature of the Password Protection component of Entra ID providing additional security for password-based authentication by enforcing both a global and a custom list of banned words for user passwords. This article aims at analyzing its implementation with the objectives to improve password spraying attacks for red team operators while providing better defenses for blue teams.

Exploiting American Conquest

16/04/2024 Back in 2023, we looked for vulnerabilities in American Conquest as a side research project. We found and reported multiple stack buffer overflow. Despite the publisher will not fix the bugs because the game is too old, we share today the details of our research. This is an interesting article for those who want to get started in researching and exploiting vulnerabilities.

VMware ESXi Forensic with Velociraptor

28/03/2024 If you are a regular Velociraptor user, you'll no doubt have noticed the introduction of new features since release 0.7.1 that extend its forensic capabilities on various systems. If not, this article will show you how to leverage those new features in order to perform forensic analysis of a VMware ESXi hypervisor.

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...