PowerShell Get-Process LSASS in ScriptBlock — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2021-04-23 / 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: abb5e82589d29cb07bad179194d602064d987420c842c9e1b03c817c6ac6621e

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 Get-Process LSASS in ScriptBlock
id: 84c174ab-d3ef-481f-9c86-a50d0b8e3edb
status: test
description: Detects a Get-Process command on lsass process, which is in almost all cases a sign of malicious activity
references:
    - https://web.archive.org/web/20220205033028/https://twitter.com/PythonResponder/status/1385064506049630211
author: Florian Roth (Nextron Systems)
date: 2021-04-23
modified: 2022-12-25
tags:
    - attack.credential-access
    - attack.t1003.001
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains: 'Get-Process lsass'
    condition: selection
falsepositives:
    - Legitimate certificate exports invoked by administrators or users (depends on processes in the environment - filter if unusable)
level: high

Original YAML and metadata in JSON

False positives

• Legitimate certificate exports invoked by administrators or users (depends on processes in the environment - filter if unusable)

Source references

• https://web.archive.org/web/20220205033028/https://twitter.com/PythonResponder/status/1385064506049630211