/pySigma

Python library to parse and convert Sigma rules into queries (and whatever else you could imagine)

Primary LanguagePythonGNU Lesser General Public License v2.1LGPL-2.1

pySigma

Tests Coverage Badge Status

pySigma is a python library that parses and converts Sigma rules into queries. It is a replacement for the legacy Sigma toolchain (sigmac) with a much cleaner design and is almost fully tested. Backends for support of conversion into query languages and processing pipelines for transforming rule for log data models are separated into dedicated projects to keep pySigma itself slim and vendor-agnostic. See the Related Projects section below to get an overview.

Getting Started

To start using pySigma, install it using your python package manager of choice. Examples:

pip install pysigma
pipenv install pysigma
poetry add pysigma

Documentation with some usage examples can be found here.

Create Your Own Backend for pySigma

The creation of a backend has become much easier with pySigma. We recommend using the "Cookie Cutter Template" and reviewing the existing backends listed in the "Related Projects" section of this README.

pySigma Cookie Cutter Template

Features

pySigma brings a number of additional features compared to sigmac, as well as some changes.

Modifier comparison between pySigma and sigmac

Modifier Use sigmac legacy
contains the value is matched anywhere in the field (strings and regular expressions) X
startswith The value is expected at the beginning of the field's content (strings and regular expressions) X
endswith The value is expected at the end of the field's content (strings and regular expressions) X
base64 The value is encoded with Base64 X
base64offset If a value might appear somewhere in a base64-encoded value the representation might change depending on the position in the overall value X
wide transforms value to UTF16-LE encoding X
re value is handled as regular expression by backends X
cidr value is handled as an IPv4 CIDR by backends (IPv6 is not supported, yet)
all This modifier changes OR logic to AND X
lt Field is less than the value
lte Field is less or egal than the value
gt Field is Greater than the value
gte Field is Greater or egal than the value
expand Modifier for expansion of placeholders in values. It replaces placeholder strings (%something%)

Backends comparison between pySigma and sigmac

On 2022/04/10

sigmac Backends Observation pySigma
ala Azure Log Analytics Queries
ala-rule Azure Log Analytics Rule
arcsight ArcSight saved search
arcsight-esm ArcSight ESM saved search
athena SQL query
carbonblack Converts Sigma rule into CarbonBlack query string
chronicle Google Chronicle YARA-L
crowdstrike CrowdStrike Search Processing Language (SPL) pySigma-pipeline-crowdstrike
csharp CSharp Regex in LINQ query
datadog-logs Datadog log search query
devo Devo query
ee-outliers ee-outliers
elastalert ElastAlert QS query
elastalert-dsl ElastAlert DSL query
es-dsl Elasticsearch DSL query pySigma-backend-elasticsearch
es-eql Elasticsearch EQL query
es-qs Elasticsearch query string. Only searches, no aggregations pySigma-backend-elasticsearch
es-qs-lr Lucene query string for LogRhythm. Only searches, no aggregations
es-rule Elastic SIEM lucene query
es-rule-eql Elastic SIEM EQL query
fieldlist List all fieldnames from given Sigma rules for creation of a field mapping configuration
fireeye-helix FireEye Helix Query Language
fortisiem Base class for Fortisem backends that generate one text-based expression from a Sigma rule
graylog Graylog query string. Only searches, no aggregations
grep Generates Perl compatible regular expressions and puts 'grep -P' around it
hawk HAWK search
humio Humio query
kibana Kibana JSON Configuration files (searches only)
kibana-ndjson Kibana JSON Configuration files (searches only) pySigma-backend-elasticsearch
lacework Lacework Policy Platform
limacharlie LimaCharlie D&R rules
logiq LOGIQ event rule api payload
logpoint LogPoint query
mdatp Microsoft Defender ATP Hunting Queries
netwitness NetWitness saved search
netwitness-epl RSA NetWitness EPL
es-qs (proxied) OpenSearch search query string. Only searches, no aggregations pySigma-backend-opensearch (proxied by pySigma-backend-elasticsearch)
es-dsl (proxied) OpenSearch DSL query pySigma-backend-opensearch (proxied by pySigma-backend-elasticsearch)
opensearch-monitor OpenSearch monitors and ElasticRule are in Elastic Common Schema pySigma-backend-opensearch
powershell PowerShell event log cmdlets
qradar Qradar saved search
qualys Qualys saved search
sentinel-rule Azure Sentinel scheduled alert rule ARM template
splunk Splunk Search Processing Language (SPL) pySigma-backend-splunk
splunkdm Splunk syntax leveraging Datamodel acceleration
splunkxml XML used for Splunk Dashboard Panels
sql SQL query
sqlite SQL query for SQLite
stix STIX pattern
sumologic SumoLogic query
sumologic-cse SumoLogic CSE query
sumologic-cse-rule SumoLogic CSE query
sysmon sysmon XML configuration
uberagent uberAgent ESA's process tagging rules
xpack-watcher X-Pack Watcher JSON for alerting

Overview

Conversion Overview

Conversion Graph

Pipelines

Conversion Graph

More details are described in the documentation.

Testing

pySigma uses pytest as testing framework. Simply run pytest to run all tests. Run pytest --cov=sigma to get a coverage report.

Building

To build your own package run poetry build.

Contributing

Pull requests are welcome. Please feel free to lodge any issues/PRs as discussion points.

This blog post by Micah Babinski explains the process from a developer's perspective.

Maintainers

The project is currently maintained by:

Related Projects

pySigma isn't a monolithic library attempting to support everything but the core. Support for target query languages and log data models is provided by additional packages that extend pySigma:

All packages can also be installed from PyPI if not mentioned otherwise by the Python package manager of your choice.

License

GNU Lesser General Public License v2.1. For details, please see the full license file located here.