Sysinternals PsSuspend Suspicious Execution — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2023-03-23 / not supplied.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 9e738e2ad6d323dff0909796d6180eba6f005094c26b8050cb851c584416fe9e

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: Sysinternals PsSuspend Suspicious Execution
id: 4beb6ae0-f85b-41e2-8f18-8668abc8af78
related:
    - id: 48bbc537-b652-4b4e-bd1d-281172df448f # Basic Execution
      type: similar
status: test
description: Detects suspicious execution of Sysinternals PsSuspend, where the utility is used to suspend critical processes such as AV or EDR to bypass defenses
references:
    - https://learn.microsoft.com/en-us/sysinternals/downloads/pssuspend
    - https://twitter.com/0gtweet/status/1638069413717975046
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-03-23
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'pssuspend.exe'
        - Image|endswith:
              - '\pssuspend.exe'
              - '\pssuspend64.exe'
    selection_cli:
        # Add more interesting/critical processes
        CommandLine|contains: 'msmpeng.exe'
    condition: all of selection_*
falsepositives:
    - Unlikely
level: high

Original YAML and metadata in JSON

False positives

• Unlikely

Source references

• https://learn.microsoft.com/en-us/sysinternals/downloads/pssuspend
• https://twitter.com/0gtweet/status/1638069413717975046