Invoke-Obfuscation VAR+ Launcher - PowerShell Module — Sigma Rule

Rule metadata and linked tags

Author: Jonathan Cheong, oscd.community. Source status: test; severity: high. Source dates: 2020-10-15 / 2024-04-05.

{
  "product": "windows",
  "category": "ps_module",
  "definition": "0ad03ef1-f21b-4a79-8ce8-e6900c54b65b"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: e91311ac9f2e3e6ae89d0e27bbcaaa98b5c16a09086bfa24723ad84b182da38a

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Invoke-Obfuscation VAR+ Launcher - PowerShell Module
id: 6bfb8fa7-b2e7-4f6c-8d9d-824e5d06ea9e
related:
    - id: 0adfbc14-0ed1-11eb-adc1-0242ac120002
      type: derived
status: test
description: Detects Obfuscated use of Environment Variables to execute PowerShell
references:
    - https://github.com/SigmaHQ/sigma/issues/1009  # (Task 24)
author: Jonathan Cheong, oscd.community
date: 2020-10-15
modified: 2024-04-05
tags:
    - attack.stealth
    - attack.t1027
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: ps_module
    definition: 0ad03ef1-f21b-4a79-8ce8-e6900c54b65b
detection:
    selection_4103:
        Payload|re: 'cmd.{0,5}(?:/c|/r)(?:\s|)"set\s[a-zA-Z]{3,6}.*(?:\{\d\}){1,}\\"\s+?-f(?:.*\)){1,}.*"'
    condition: selection_4103
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/SigmaHQ/sigma/issues/1009