README.md

pySigma tql Backend

This is the tql backend for pySigma. It provides the package sigma.backends.trellix-helix with the tqlBackend class. Further, it contains the following processing pipelines in sigma.pipelines.trellix-helix:

It supports the following output formats:

• default: plain tql queries

This backend is currently maintained by:

• Saw Win Naung

Usage example

Sigma CLI

You can quickly convert a single rule or rules in a directory structure using Sigma CLI. You can use: sigma convert -t tqlBackend -s ~/sigma/rules where -t is the target query language and -s is the Sigma rule or rules directory you wish to convert.

Stand-alone Script

The following example script demonstrates how you can use the Helix backend to generate TQL queries for the following Sigma rules:

python trellix_helix.py ../../sigma/rules-threat-hunting/windows/process_creation

# demonstrates basic usage of InsightIDR backend
from sigma.collection import SigmaCollection
from sigma.backends.trellixhelix import tqlBackend

# create pipeline and backend
trellixhelix_backend = tqlBackend()

# load a ruleset
process_start_rules = [r"C:\SigmaRules\rules\windows\process_creation\proc_creation_win_webshell_detection.yml",
                       r"C:\SigmaRules\rules\windows\process_creation\proc_creation_win_cmd_delete.yml",
                       r"C:\SigmaRules\rules\windows\process_creation\proc_creation_win_susp_rundll32_activity.yml"]

process_start_rule_collection = SigmaCollection.load_ruleset(process_start_rules)

# convert the rules
for rule in process_start_rule_collection.rules:
    print(rule.title + " conversion:")
    print(trellixhelix_backend.convert_rule(rule)[0])
    print("\n")

Side Notes & Limitations

• Backend uses Trellix TQL
• Pipeline uses Trellix Helix field names
• Pipeline supports windows product types other will be supported
• Pipeline supports the following category types
  • process_creation
  • file
  • file_event
  • dns_query
• Any unsupported fields or categories will throw errors