Rule Document 1:66984

Rule Category

MALWARE-CNC -- Snort has detected a Comand and Control (CNC) rule violation, most likely for commands and calls for files or other stages from the control server. The alert indicates a host has been infiltrated by an attacker, who is using the host to make calls for files, as a call-home vector for other malware-infected networks, for shuttling traffic back to bot owners, etc.

Alert Message

MALWARE-CNC Win.Rat.ClosedQuorum outbound connection attempt

Rule Explanation

This rule looks for specially crafted LLM chat completion messages associated with Win.Rat.ClosedQuorum. ClosedQuorum is an autonomous agent like malware that uses commercial cloud models to drive its execution on infected environment.

What To Look For

This rule alerts on AI prompt queries from Win.Rat.ClosedQuorum.

Known Usage

Attacks/Scans seen in the wild

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group