Hey, it’s been a while. Today we’re diving into a multi-stage post-compromise investigation that highlights an Initial Access Broker (IAB) handing off access to a buyer. This campaign involved layered C2 infrastructure, subtle persistence mechanisms, and anti-analysis tactics across multiple remote management tools.

The initial alert stemmed from an end-user seeing a visible error message. That single artifact pulled our team down a rabbit hole, eventually revealing a complex chain of initial entry, persistence staging, and access resale.

Welcome back to my blog today I’m going to be going over something I haven’t worked on since I was messing around on TryHackMe for my initial training with Atomic Red Team.

As of right now at my current position most of the team is comprised of standard helpdesk employees and I was hoping I could bridge the gap between security and helpdesk and hopefully get someone interested into security.

Threat Analysis: MeshAgent Sleeper RMM and Attempted BDE Key Exfiltration

Initial Information

I wanted to start this off by saying I had never heard of mesh agent previously up until this point. Essentially it is an Open Source RMM tool with a 2010 style UI. It allows for capabilities that many other RMM tools offer which can be used for legitmate purposes aswell as malicious ones.

This post we’re going to go into the attack lifecycle of the attack some lessons learned and key points regarding the initial compromise.

Threat actors are increasingly abandoning custom malware for simple, built in native binaries. This strategy is known as Living off the land (LotL). It turns tools that are used for legitimate administrative purposes against the machine making it hard to detect.

Recently when remediating an incident within an organization we observed the textbook example of this attack chain. The attack used a clever social engineering tactic known as ClickFix with legacy windows protocols to establish persistence, and deploy rogue RMM software on the environment.