Cobalt Strike: Using Known Private Keys To Decrypt Traffic – Part 2

We decrypt Cobalt Strike traffic using one of 6 private keys we found. In this blog post, we will analyze a Cobalt Strike infection by looking at a full packet capture that was taken during the infection. This analysis includes decryption of the C2 traffic. If you haven't already, we invite you to read part … Continue reading Cobalt Strike: Using Known Private Keys To Decrypt Traffic – Part 2

Automate, automate, automate: Three Ways to Increase the Value from Third Party Risk Management Efforts

Third Party Risk Management (“TPRM”) efforts are often considered labour-intensive, with numerous tedious, manual steps. Often, an equal amount of effort is put into managing the process as is to focusing on risks. In order to avoid this, we’d like to share three ways in which we’ve been boosting our own TPRM efficiency - through … Continue reading Automate, automate, automate: Three Ways to Increase the Value from Third Party Risk Management Efforts

Kernel Karnage – Part 1

I start the first week of my internship in true spooktober fashion as I dive into a daunting subject that’s been scaring me for some time now: The Windows Kernel. 1. KdPrint(“Hello, world!\n”); When I finished my previous internship, which was focused on bypassing Endpoint Detection and Response (EDR) software and Anti-Virus (AV) software from … Continue reading Kernel Karnage – Part 1

Cobalt Strike: Using Known Private Keys To Decrypt Traffic – Part 1

We found 6 private keys for rogue Cobalt Strike software, enabling C2 network traffic decryption. The communication between a Cobalt Strike beacon (client) and a Cobalt Strike team server (C2) is encrypted with AES (even when it takes place over HTTPS). The AES key is generated by the beacon, and communicated to the C2 using … Continue reading Cobalt Strike: Using Known Private Keys To Decrypt Traffic – Part 1

All aboard the internship – whispering past defenses and sailing into kernel space

Previously, we have already published Sander's (@cerbersec) internship testimony. Since this post does not really contain any juicy technical details and Sander has done a terrific job putting together a walkthrough of his process, we thought it would be a waste not to highlight his previous posts again. In Part 1, Sander explains how he … Continue reading All aboard the internship – whispering past defenses and sailing into kernel space

Building an ICS Firing Range – Part 2 (Defcon 29 ICS Village)

As discussed in our first post in the series about our ICS firing range, we came to the conclusion that we had to build a lab ourselves. Now, this turned out to be a quite tricky task and in this blog post I am going to tell you why: which challenges we faced and which … Continue reading Building an ICS Firing Range – Part 2 (Defcon 29 ICS Village)

Kusto hunting query for CVE-2021-40444

Introduction On September 7th 2021, Microsoft published customer guidance concerning CVE-2021-40444, an MSHTML Remote Code Execution Vulnerability: Microsoft is investigating reports of a remote code execution vulnerability in MSHTML that affects Microsoft Windows. Microsoft is aware of targeted attacks that attempt to exploit this vulnerability by using specially-crafted Microsoft Office documents.An attacker could craft a … Continue reading Kusto hunting query for CVE-2021-40444

Anatomy and Disruption of Metasploit Shellcode

In April 2021 we went through the anatomy of a Cobalt Strike stager and how some of its signature evasion techniques ended up being ineffective against detection technologies. In this blog post we will go one level deeper and focus on Metasploit, an often-used framework interoperable with Cobalt Strike. Throughout this blog post we will … Continue reading Anatomy and Disruption of Metasploit Shellcode