SCRT Team Blog – Orange Cyberdefense Switzerland's technical blog

Blinding EDRs: A deep dive into WFP manipulation

This article complements existing research referenced in the Further Reading section.

Endpoint Detection and Response (EDR) solutions are essential to modern defensive architectures. Their abilities to monitor, block, and respond to threats are important for containment and remediation. However, like all complex systems, EDRs rely on components that can be turned against them. One of those components is the Windows Filtering Platform (WFP), which many EDRs leverage for network traffic control and endpoint isolation.

In this article, we explore how WFP can be manipulated to either block an EDR’s connection to its cloud backend or bypass its isolation mechanisms. Both cases can effectively “blind” the EDR or reduce its effectiveness.

We observed that certain EDRs show reduced detection and response capabilities when disconnected from their cloud infrastructure. This prompted us to investigate how WFP configuration can affect an EDR’s cloud communication. During testing, we found that the same mechanism underpins the product’s “isolation” mode, meaning that manipulating WFP rules can also be leveraged to bypass its network containment features.

SonicDoor – Cracking SonicWall’s SMA 500

While attempting to compare the security level of various VPN vendors, I kept falling down the path of searching for vulnerabilities instead. This blog post details the ones I discovered in SonicWall’s SMA 500, which were patched in December 2024. This post has been delayed to coincide with my talk at SecurityFest on this exact subject.

Hijacking the Windows “MareBackup” Scheduled Task for Privilege Escalation

The built-in “MareBackup” scheduled task is susceptible to a trivial executable search order hijacking, which can be abused by a low-privileged user to gain SYSTEM privileges whenever a vulnerable folder is prepended to the system’s PATH environment variable (instead of being appended).

Insomni’hack 2025 – GuLosity writeup

The challenge

A malware was provided from a real DFIR case that occurred in January 2024. The final payloads were disarmed here, to allow the analysts to dissect the binary safely until they fully understand the execution chain of a reflective shellcode loader named GuLoader [which initially led to the delivery of Remcos RAT with an additional keylogger, but the original nasty shellcodes were replaced by benign ones to provide the most realistic challenge].

Reinventing PowerShell in C/C++

I like PowerShell, I like it a lot! I like its versatility, its ease of use, its integration with the Windows operating system, but it also has a few features, such as AMSI, CLM, and other logging capabilities, that slow it down. You know, I’m thinking about the performance gain here. I believe my scripts could run a lot faster without them.

Jokes aside, I know that a lot has already been done around this subject, but I wanted to approach the problem in a slightly different way than the existing projects. So, I worked on a way to instantiate a full-blown PowerShell console using only native code, which allowed me to do some “cleaning” at the same time.

Attacking Cortex XDR from an unprivileged user perspective

In late 2023, we launched a new form of service where multiple customers could co-fund research time on a given product they are all using. The goal of the Co-funded research is to find vulnerabilities and possible weaknesses within the product that could impact not only our customers’ security, but anyone using the product. The discovered vulnerabilities are then reported to the editor of the solution and temporary mitigation options or IOCs are provided to the customers’ who funded the research.

In this context, we put some effort into the analysis of Cortex XDR and identified some interesting findings.

This blog post details two vulnerabilities (CVE-2024-5907 and CVE-2024-9469) that have now been fixed by Palo Alto and which could at the time be exploited by a low privileged user.

This research on Cortex XDR was performed by Florian Audon (@Nodauf) and Romain Melchiorre (@PMa1n).

Arbitrary web root file read in Sitecore before v10.4.0 rev. 010422

As part of our continuous pentesting offering, we try to identify solutions used by multiple clients to guide our research efforts to deliver the greatest impact. That is why, recently, we spent some time searching for vulnerabilities within Sitecore to find what we initially thought to be a 0-day, but ended up having been already patched some time earlier.

Exploiting KsecDD through Server Silos

Earlier this year, an intriguing admin-to-kernel technique was published by @floesen_ in the form of a proof-of-concept (PoC) on GitHub. The author mentioned a strong limitation involving LSASS and Server Silos, without providing much details about it. This piqued our interest, so we decided to give it a second look…

Privilege escalation through TPM Sniffing when BitLocker PIN is enabled

This blog post offers additional insights following the presentation delivered at the Swiss Cyber Storm conference in Bern on October 22, 2024.