Windows Defender AMSI Trigger Detected — Sigma Rule

Rule metadata and linked tags

Author: Bhabesh Raj. Source status: stable; severity: high. Source dates: 2020-09-14 / 2022-12-07.

{
  "product": "windows",
  "service": "windefend"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 76237a7d942e4731124ba5cf0d9b85bb8f62ba0a55e85d072e56cb0b9e2e3030

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: Windows Defender AMSI Trigger Detected
id: ea9bf0fa-edec-4fb8-8b78-b119f2528186
status: stable
description: Detects triggering of AMSI by Windows Defender.
references:
    - https://learn.microsoft.com/en-us/windows/win32/amsi/how-amsi-helps
author: Bhabesh Raj
date: 2020-09-14
modified: 2022-12-07
tags:
    - attack.execution
    - attack.t1059
logsource:
    product: windows
    service: windefend
detection:
    selection:
        EventID: 1116 # The antimalware platform detected malware or other potentially unwanted software.
        SourceName: 'AMSI'
    condition: selection
falsepositives:
    - Unlikely
level: high

Original YAML and metadata in JSON

False positives

• Unlikely

Source references

• https://learn.microsoft.com/en-us/windows/win32/amsi/how-amsi-helps