pySigma PowerShell Backend

The pySigma PowerShell backend uses pySigma to convert Sigma rules into PowerShell queries. It was designed to be used in conjunction with the Soap PowerShell module (i.e., the Read-WinEvent function).

Overview

The pySigma PowerShell backend includes two Python packages:

• sigma.pipelines.powershell: normalizes Sigma rules for PowerShell.
• sigma.backends.powershell: declares the PowerShellBackend class and multiple output methods.

It currently supports the following output formats:

• default: plain PowerShell queries
• script: a PowerShell script
• xml: XML documents
• xpath: XML strings
• subscription: Windows event subscriptions

Usage

poetry run python sigma2powershell.py -p rules/

Testing

python -m pip install --user pytest
python -m pytest                                                                  # test all functions
python -m pytest tests/test_backend_powershell.py::test_powershell_and_expression # test a specific function

Updating to the Latest Version of pySigma

python -m poetry add pysigma@latest

References

• Understanding XML and XPath by the Microsoft Scripting Guy, Ed Wilson