Definition
A Command and Control (C2) framework is the centralized software used by threat actors to communicate with compromised systems (implants/beacons) within a victim's network. Modern C2 frameworks provide a dashboard for the attacker to execute commands, move laterally, and exfiltrate data.
Purpose and Core Idea
Historically, attackers wrote custom C2 code. Today, they rely on commercial or open-source "Red Team" frameworks. These tools are designed for security testing but are widely abused by criminals because they are stable, feature-rich, and difficult to attribute.
Mini Case Study: Cobalt Strike & The "Cracked" Market
Cobalt Strike is a legitimate threat emulation tool, but it is the most abused C2 framework in history.
- The Beacon: Its payload, known as "Beacon," is highly malleable. It can change its traffic signature (Jitter, User-Agent) to look like Amazon browsing or Google updates.
- The Incident: In the Ryuk Ransomware campaigns, the attackers used cracked versions of Cobalt Strike. CTI analysts were able to fingerprint these cracked servers because they shared a specific default SSL certificate and port configuration (Port 50050).
- The Shift: As Cobalt Strike signatures became well-known, sophisticated groups (like APT29) moved to newer frameworks like Brute Ratel and Sliver to evade detection.
Usage in Real CTI Workflows CTI analysts use OSINT tools like Shodan to scan the internet for C2 servers (Team Servers) exposed with default configurations. Identifying a C2 server allows defenders to block the IP before the malware is even deployed.
Relation to Other CTI Frameworks C2 activity corresponds to the "Command and Control" tactic in MITRE ATT&CK and the 6th step of the Cyber Kill Chain.