CrossC2 Expanding Cobalt Strike Beacon to Cross-Platform Attacks

Description

From September to December 2024, incidents involving CrossC2, an extension tool for Cobalt Strike Beacon on Linux, were confirmed. The attacker used CrossC2 along with other tools like PsExec, Plink, and Cobalt Strike to penetrate AD. A custom malware called ReadNimeLoader was used as a loader for Cobalt Strike. The campaign may have affected multiple countries. CrossC2 is an unofficial Beacon and builder compatible with Cobalt Strike 4.1+, designed for Linux and macOS. It contains anti-analysis features and encrypted configuration data. The attack flow involved java.exe, ReadNimeLoader, and OdinLdr to execute Cobalt Strike Beacon. Other tools used include SystemBC, GetNPUsers, and privilege escalation tools. The campaign shows potential connections to BlackBasta based on similar characteristics.