Detection rules › Sigma

Python Path Configuration File Creation - MacOS

Status
test
Severity
medium
Log source
product macos, category file_event
Author
Andreas Braathen (mnemonic.io)
Source
github.com/SigmaHQ/sigma

Detects creation of a Python path configuration file (.pth) in Python library folders, which can be maliciously abused for code execution and persistence. Modules referenced by these files are run at every Python startup (v3.5+), regardless of whether the module is imported by the calling script. Default paths are '\lib\site-packages*.pth' (Windows) and '/lib/pythonX.Y/site-packages/*.pth' (Unix and macOS).

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
ESFcreateFile or Directory Create (NOTIFY)

Rule body yaml

title: Python Path Configuration File Creation - MacOS
id: 4f394635-13ef-4599-b677-3353e0f84f55
related:
    - id: e3652ba3-0ad8-4010-a957-b7ba369e7bac # Windows
      type: similar
    - id: fb96c26c-9f85-4ae7-af0d-ed1ed1f1f5ce # Linux
      type: similar
status: test
description: |
    Detects creation of a Python path configuration file (.pth) in Python library folders, which can be maliciously abused for code execution and persistence.
    Modules referenced by these files are run at every Python startup (v3.5+), regardless of whether the module is imported by the calling script.
    Default paths are '\lib\site-packages\*.pth' (Windows) and '/lib/pythonX.Y/site-packages/*.pth' (Unix and macOS).
references:
    - https://www.volexity.com/blog/2024/04/12/zero-day-exploitation-of-unauthenticated-remote-code-execution-vulnerability-in-globalprotect-cve-2024-3400/
    - https://www.virustotal.com/gui/file/3de2a4392b8715bad070b2ae12243f166ead37830f7c6d24e778985927f9caac
    - https://docs.python.org/3/library/site.html
author: Andreas Braathen (mnemonic.io)
date: 2024-04-25
tags:
    - attack.execution
    - attack.t1059.006
    - detection.threat-hunting
logsource:
    product: macos
    category: file_event
detection:
    selection:
        TargetFilename|re: '(?i)/lib/python3\.([5-9]|[0-9]{2})/site-packages/' # Unix and macOS
        TargetFilename|endswith: '.pth'
    condition: selection
falsepositives:
    - Although .pth files are discouraged due to potential security implications, these are legitimate files by specification.
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetFilename|re: '(?i)/lib/python3\.([5-9]|[0-9]{2})/site-packages/'
    TargetFilename|endswith: '.pth'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
TargetFilenameends_with
  • .pth
TargetFilenameregex_match
  • (?i)/lib/python3.([5-9]|[0-9]{2})/site-packages/