Potential Python DLL SideLoading — Sigma Rule

Rule metadata and linked tags

Author: Swachchhanda Shrawan Poudel. Source status: test; severity: medium. Source dates: 2024-10-06 / 2025-08-18.

{
  "category": "image_load",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 713105a093ce4d3d97478e0a40ee35dd3915e7ab417f0fe527b90e314488c885

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential Python DLL SideLoading
id: d36f7c12-14a3-4d48-b6b8-774b9c66f44d
status: test
description: Detects potential DLL sideloading of Python DLL files.
references:
    - https://www.securonix.com/blog/seolurker-attack-campaign-uses-seo-poisoning-fake-google-ads-to-install-malware/
    - https://thedfirreport.com/2024/09/30/nitrogen-campaign-drops-sliver-and-ends-with-blackcat-ransomware/
    - https://github.com/wietze/HijackLibs/tree/dc9c9f2f94e6872051dab58fbafb043fdd8b4176/yml/3rd_party/python
author: Swachchhanda Shrawan Poudel
date: 2024-10-06
modified: 2025-08-18
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith:
            - '\python39.dll'
            - '\python310.dll'
            - '\python311.dll'
            - '\python312.dll'
    filter_main_default_install_paths:
        - ImageLoaded|startswith:
              - 'C:\Program Files\Python3'
              - 'C:\Program Files (x86)\Python3'
        - ImageLoaded|contains: '\AppData\Local\Programs\Python\Python3'
    filter_optional_visual_studio:
        ImageLoaded|startswith: 'C:\Program Files\Microsoft Visual Studio\'
    filter_optional_anaconda:
        ImageLoaded|startswith: 'C:\ProgramData\Anaconda3\' # Comment out if you don't use Anaconda in your environment
    filter_optional_cpython:
        ImageLoaded|contains:
            - '\cpython\externals\'
            - '\cpython\PCbuild\'
    filter_optional_pyinstaller:
        # Triggered by programs bundled with PyInstaller
        ImageLoaded|startswith: 'C:\Users'
        ImageLoaded|contains: '\AppData\Local\Temp\_MEI'
    filter_main_legit_signature_details:
        Product: 'Python'
        Signed: 'true'
        Description: 'Python'
        Company: 'Python Software Foundation'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Legitimate software using Python DLLs
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate software using Python DLLs

Source references

• https://www.securonix.com/blog/seolurker-attack-campaign-uses-seo-poisoning-fake-google-ads-to-install-malware/
• https://thedfirreport.com/2024/09/30/nitrogen-campaign-drops-sliver-and-ends-with-blackcat-ransomware/
• https://github.com/wietze/HijackLibs/tree/dc9c9f2f94e6872051dab58fbafb043fdd8b4176/yml/3rd_party/python