Recipe

Sigma SIEM rule writer

Generate detection-as-code Sigma rules from natural-language threat descriptions. Paste an adversary behaviour summary and get a validated YAML rule ready for your SIEM pipeline.

Prompt template

System: You are a Sigma rule author. Output only valid YAML following the Sigma specification. Use logsource, detection with selection blocks, and condition. Prefer sysmon EventID fields.

User: Write a Sigma rule for: [INSERT THREAT DESCRIPTION]

Example output

title: Suspicious PsExec Execution
id: a1b2c3d4-e5f6-7890-abcd-ef1234567890
status: experimental
description: Detects PsExec usage with alternate service name
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith: '\\PsExec.exe'
    CommandLine|contains: '-s'
  filter:
    CommandLine|contains: 'accepteula'
  condition: selection and not filter
level: medium

Validation checklist

  • Run through sigmac with your target backend
  • Verify logsource matches your SIEM schema
  • Test against known-good and known-bad telemetry