Glossary

    C2 Server (Command and Control)

    Incident Response

    A C2 (Command and Control) server is infrastructure operated by an attacker to communicate with compromised systems. It serves two functions: sending instructions to malware running on victim machines, and receiving exfiltrated data.

    How C2 Works in Cloud Attacks

    • Data exfiltration: stolen credentials are encrypted (often AES-256 + RSA-4096) and POSTed to C2 endpoints
    • Domain mimicry: C2 domains often mimic legitimate services (e.g., models.litellm.cloud mimicking the real litellm.ai)
    • Persistence polling: backdoors periodically check the C2 for new payloads to execute
    • Kill switches: some C2 implementations include deactivation mechanisms

    Detection in AWS

    • GuardDuty: detects EC2 instances communicating with known C2 servers
    • VPC Flow Logs: identify unusual outbound connections
    • Route 53 Resolver DNS Firewall: block DNS resolution of known malicious domains
    • CloudTrail: detect unusual API calls from compromised credentials

    Related AWS Services

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