WMI Persistence - Script Event Consumer

Hunt Hypothesis

Detects WMI script event consumers

Detection Rule

Sigma (Original)

title: WMI Persistence - Script Event Consumer
id: ec1d5e28-8f3b-4188-a6f8-6e8df81dc28e
status: test
description: Detects WMI script event consumers
references:
    - https://www.eideon.com/2018-03-02-THL03-WMIBackdoors/
author: Thomas Patzke
date: 2018-03-07
modified: 2022-10-11
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1546.003
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image: C:\WINDOWS\system32\wbem\scrcons.exe
        ParentImage: C:\Windows\System32\svchost.exe
    condition: selection
falsepositives:
    - Legitimate event consumers
    - Dell computers on some versions register an event consumer that is known to cause false positives when brightness is changed by the corresponding keyboard button
level: medium

KQL (Azure Sentinel)

imProcessCreate
| where TargetProcessName =~ "C:\\WINDOWS\\system32\\wbem\\scrcons.exe" and (ParentProcessName =~ "C:\\Windows\\System32\\svchost.exe" or ActingProcessName =~ "C:\\Windows\\System32\\svchost.exe")

Required Data Sources

False Positive Guidance

• Legitimate event consumers
• Dell computers on some versions register an event consumer that is known to cause false positives when brightness is changed by the corresponding keyboard button

MITRE ATT&CK Context

• Tactic: Persistence
• Tactic: Privilege Escalation
• Technique: T1546.003 — T1546.003

References

• https://www.eideon.com/2018-03-02-THL03-WMIBackdoors/
• SigmaHQ Rule