- AN0713 · Analytic 0713 — Defender observes unauthorized modification or creation of Python hook files such as `.pth`, `sitecustomize.py`, or `usercustomize.py` in Python `site-packages`, `dist-packages`, or user paths. This is often correlated with subsequent unexpected interpreter execution (e.g., python3 running without user interaction), changes in interpreter behavior (e.g., malicious imports), and outbound connections initiated from Python. Defender links write/modify actions on hook files with execve of python process and/or anomalous child process or network activity.
Python Startup Hooks
Adversaries may achieve persistence by leveraging Python’s startup mechanisms, including path configuration (`.pth`) files and the `sitecustomize.py` or `usercustomize.py` modules. These files are automatically processed during the initialization of the Python interpreter, allowing for the execution of arbitrary code whenever Python is invoked.(Citation: Volexity GlobalProtect CVE 2024) Path configuration files are designed to extend Python’s module search paths through the use of import statements. If a `.pth` file is placed in Python's `site-packages` or `dist-packages` directories, any lines beginning with `import` will be executed automatically on Python invocation.(Citation: DFIR Python Persistence 2025) Similarly, if `sitecustomize.py` or `usercustomize.py` is present in the Python path, these files will be imported during interpreter startup, and any code they contain will be executed.(Citation: Python Site Configuration Hook) Adversaries may abuse these mechanisms to establish persistence on systems where Python is widely used (e.g., for automation or scripting in production environments).
Open in the interactive knowledge mesh
Detection overview
Use the published detection strategies below and validate required telemetry in the target environment.
Observed groups
No current Enterprise group relationship is published in this bundle.
Cyber Knowledge context
Use these routes to move from the ATT&CK behavior into explanation, implementation, evidence handling, validation, and defensive operations. Relevance is generated from explicit identifiers/names and governed topic mappings; it is not attribution evidence.
Red Team & Offensive Security · tactic-route · 24/100Module 4 — Detection engineering and detection as code
Blue Team & Defensive Security · tactic-route · 24/100Disk, file-system, and persistence forensics
Digital Forensics & Incident Response (DFIR) · tactic-route · 24/100Binary formats, ABI, loaders, and mitigations
Vulnerability Research & Exploit Development · tactic-route · 24/100Network, edge, service communication, hybrid access, and zero trust
Cloud Security · tactic-route · 24/100
MITRE mitigations
No ATT&CK mitigation relationship is published for this technique. Apply risk-based controls and verify scope.