Brute Ratel C4

Brute Ratel C4 (BRC4) is a commercial framework for red-teaming and adversarial attack simulation, which made its first appearance in December 2020. It was specifically designed to evade detection by endpoint detection and response (EDR) and antivirus (AV) capabilities. BRC4 allows operators to deploy a backdoor agent known as Badger (aka BOLDBADGER) within a target environment.

This agent enables arbitrary command execution, facilitating lateral movement, privilege escalation, and the establishment of additional persistence avenues. The Badger backdoor agent can communicate with a remote server via DNS over HTTPS, HTTP, HTTPS, SMB, and TCP, using custom encrypted channels. It supports a variety of backdoor commands including shell command execution, file transfers, file execution, and credential harvesting. Additionally, the Badger agent can perform tasks such as port scanning, screenshot capturing, and keystroke logging. Notably, in September 2022, a cracked version of Brute Ratel C4 was leaked in the cybercriminal underground, leading to its use by threat actors.