sigmamediumHunting

WMI Persistence - Script Event Consumer

Detects the execution of a script event consumer. When scrcons.exe launches, it does so in response to the creation of an ActiveScriptEventConsumer instance and will execute registered JScript or VBScript code as a result. Script event consumers are a built-in Windows Management Instrumentation (WMI) class that automatically executes a predefined script (in VBScript or JScript) whenever a specific system event occurs. Adversaries often abuse script event consumers to maintain persistence on a compromised host by executing a malicious script whenever a specific event occurs.

MITRE ATT&CK

T1546.003

persistenceprivilege-escalation

Detection Query

selection:
  Image: C:\WINDOWS\system32\wbem\scrcons.exe
  ParentImage: C:\Windows\System32\svchost.exe
condition: selection

Author

Thomas Patzke

Created

2018-03-07

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.persistenceattack.privilege-escalationattack.t1546.003

Raw Content

title: WMI Persistence - Script Event Consumer
id: ec1d5e28-8f3b-4188-a6f8-6e8df81dc28e
status: test
description: |
    Detects the execution of a script event consumer. When scrcons.exe launches, it does so in response to the creation of an ActiveScriptEventConsumer instance
    and will execute registered JScript or VBScript code as a result.
    Script event consumers are a built-in Windows Management Instrumentation (WMI) class that
    automatically executes a predefined script (in VBScript or JScript) whenever a specific system event occurs.
    Adversaries often abuse script event consumers to maintain persistence on a compromised host
    by executing a malicious script whenever a specific event occurs.
references:
    - https://redcanary.com/blog/threat-detection/child-processes/
    - 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