Powershell Store File In Alternate Data Stream — Sigma Rule

Rule metadata and linked tags

Author: frack113. Source status: test; severity: medium. Source dates: 2021-09-02 / 2022-12-25.

{
  "product": "windows",
  "category": "ps_script",
  "definition": "Requirements: Script Block Logging must be enabled"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: a730f3360a91288bf7924a4802117e2c0283c162acda4ef1091031cf6aef4eaa

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: Powershell Store File In Alternate Data Stream
id: a699b30e-d010-46c8-bbd1-ee2e26765fe9
status: test
description: Storing files in Alternate Data Stream (ADS) similar to Astaroth malware.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1564.004/T1564.004.md
author: frack113
date: 2021-09-02
modified: 2022-12-25
tags:
    - attack.stealth
    - attack.t1564.004
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection_compspec:
        ScriptBlockText|contains|all:
            - 'Start-Process'
            - '-FilePath "$env:comspec" '
            - '-ArgumentList '
            - '>'
    condition: selection_compspec
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1564.004/T1564.004.md