SIEGMA

This project aims to automate the creation of SIEM rule consumables by leveraging a pre-defined set of configurations/mappings and by utilizing the Sigma rule format and engine.

It is also our objective to take a community approach to SIEM schemas, maintaining easy to read data dictionaries while making it trivial to add custom fields based on specific use cases.

For platforms that support it, SIEGMA also enables automatic upload of the SIEM consumable. Check the Automatic Import section for more information.

How does it differ from sigmac? The reason we decided to create our own artifacts is to have more control over the mappings and allow for a different level of automation. This project is not mean to be a replacement to Sigma or sigmac, especially since it utilizes sigmac.

Supported SIEM's

• Elastic SIEM
• Azure Sentinel
• Splunk (in development)

Installation

We'll run the software and install dependencies, for both this project as well as Sigma, under a Python virtual environment.

pip3 install pipenv

• Setup Sigma

git clone https://github.com/Neo23x0/sigma
cd sigma
pipenv install --skip-lock

• Setup SIEGMA

git clone https://github.com/3CORESec/SIEGMA
cd SIEGMA
pipenv install

Note for Windows users: Powershell must be enabled for command and script execution. Open Administrative Powershell and execute following command: Set-ExecutionPolicy Bypass

Before running SIEGMA: Sigma rules might not hold all required fields in use by your SIEM. To make sure that all fields are mapped correctly, each product holds a README where we warn you if there are fields that need to be filled before running this software.

Visit your SIEM config folder to learn more about this.

Usage

Invoke the script by providing it a Sigma rule or Sigma rule folder as well as the desired SIEM platform.

Activate the virtual environment:

pipenv shell

It is recommended to consult the siegma.py help, especially for advanced usage instructions:

python siegma.py -h

In order to provide examples for each specific platform, we have moved the examples section to their own README section inside of the config folder of the SIEM in question.

Please consult each SIEM folder for detailed instructions on how to convert single Sigma files, folders, automatic upload and other options.

Rules compliance

SIEGMA natively makes use of this script for rule format compliance check.

However, to manually check if the rules are in the correct format and processable by SIEGMA, run following commands:

cd helpers
python check_if_compliant.py -p path/to/rules/directory/

SIEM Automatic Import

As part of our objective of developing tools, techniques and know-how to Detection as Code, it has always been the goal of this project to allow the usage of SIEGMA in a CI/CD pipeline. Please consult the README of the desired SIEM for additional information on how to enable this feature.

Contributions and Development

Want to know more how it all comes together or want to contribute support for a new platform? Check the development guide for more information.

Roadmap

• Additional platform/SIEM support
  • Elastic SIEM
  • Azure Sentinel
  • Splunk (To be developed)
• Additional Features
  • Elastic
    • Actions support

Feedback

Found this interesting? Have a question/comment/request? Let us know!

Feel free to open an issue or ping us on Twitter.