WMI Persistence - Script Event Consumer

 Original Source: [Sigma source]
Title: WMI Persistence - Script Event Consumer
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