Malicious AdaptixC2 Beacon via X-Beacon-Id Header and Default User Agent (via proxy)

ATT&CK techniques

C2

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.001Web Protocols
Exfiltration
Impact

What it detects

This rule detects HTTP traffic carrying the AdaptixC2 specific X-Beacon-Id header or the framework default Firefox 20.0 user agent string. AdaptixC2 is a post-exploitation command-and-control framework used for beaconing and tunneling. Detecting either the custom header or the anachronistic user agent exposes agent check-ins to an AdaptixC2 listener.

Reporting behind it

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Malicious AdaptixC2 Beacon via X-Beacon-Id Header and Default User Agent (via proxy)

Pivot detection · T1071.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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