Windows Security Event 4697: mshta Script Obfuscation Indicators

Detects service creation where the binary path includes mshta plus VBS/automation indicators consistent with script-based obfuscation.

FreeUnreviewedSigmahighv1

windows-security-event-4697-mshta-script-obfuscation-indicators-9b8d9203

title: "Windows Security Event 4697: mshta Script Obfuscation Indicators"
id: c7608674-23dd-4a83-b9bb-965c4c5f5ec8
related:
  - id: 7e9c7999-0f9b-4d4a-a6ed-af6d553d4af4
    type: derived
  - id: 9b8d9203-4e0f-4cd9-bb06-4cc4ea6d0e9a
    type: derived
status: test
description: "This rule flags Windows System Security Extension events where a new service binary path contains mshta along with multiple script-automation indicators: vbscript:createobject, .run, and window.close. Attackers often use mshta to execute script content indirectly, a common approach to evade straightforward command-line inspection. The detection relies on Security log EventID 4697 and matches substrings within the recorded service file name for mshta and its embedded script patterns."
references:
  - https://github.com/SigmaHQ/sigma/issues/1009
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_invoke_obfuscation_via_use_mshta_services_security.yml
author: Nikita Nazarov, oscd.community, Huntrule Team
date: 2020-10-09
modified: 2022-11-29
tags:
  - attack.stealth
  - attack.t1027
  - attack.execution
  - attack.t1059.001
logsource:
  product: windows
  service: security
  definition: The 'System Security Extension' audit subcategory need to be enabled to log the EID 4697
detection:
  selection:
    EventID: 4697
    ServiceFileName|contains|all:
      - mshta
      - vbscript:createobject
      - .run
      - window.close
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1

What it detects

This rule flags Windows System Security Extension events where a new service binary path contains mshta along with multiple script-automation indicators: vbscript:createobject, .run, and window.close. Attackers often use mshta to execute script content indirectly, a common approach to evade straightforward command-line inspection. The detection relies on Security log EventID 4697 and matches substrings within the recorded service file name for mshta and its embedded script patterns.

Known false positives

Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.