Malicious Koi Loader C2 Check-in via Index PHP Beacon (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 Koi Loader command-and-control beacons to an index.php endpoint carrying the campaign-specific subid=px8eIkut parameter used for host registration. This structured query pattern accompanies the pipe-delimited 101|GUID|VoYGkc5R check-in marker. Detecting it surfaces active Koi Loader C2 that precedes Koi Stealer deployment and credential exfiltration.

Reporting behind it

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Malicious Koi Loader C2 Check-in via Index PHP Beacon (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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