Suspicious Python Site Hook or PTH File Written to Site-Packages via File Event

ATT&CK techniques

Persistence → Priv Esc

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1546Event Triggered Execution
Priv Esc
- T1546Event Triggered Execution
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the creation of Python site-initialization hooks sitecustomize.py and usercustomize.py or a .pth file inside site-packages, the persistence mechanism used by the malicious Python packages reported by Cisco Talos. These files execute automatically every time the interpreter starts, giving attackers durable code execution. Detecting writes of these hooks reveals stealthy persistence planted through the packaging ecosystem.

Reporting behind it

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Suspicious Python Site Hook or PTH File Written to Site-Packages via File Event

Pivot detection · T1546 · 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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