Possible Origin Logger C2 Exfiltration via Hardcoded User Agent and Gate Endpoints via proxy

ATT&CK techniques

Cred Access → C2

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
- T1555.003Credentials from Web Browsers
Discovery
Lateral Movement
Collection
C2
- T1071.001Web Protocols
Exfiltration
Impact

What it detects

This rule detects Origin Logger keylogger command and control traffic that beacons with a hardcoded Firefox/99.0 user agent to /gate and /login exfiltration endpoints. Origin Logger is an AgentTesla derived stealer that harvests browser credentials and web session data. Correlating the fixed user agent with the exfil URI paths surfaces credential theft egress while suppressing benign Firefox browsing.

Reporting behind it

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Possible Origin Logger C2 Exfiltration via Hardcoded User Agent and Gate Endpoints 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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