Suspicious Microsoft Office Child Process - MacOS — Sigma Rule

Rule metadata and linked tags

Author: Sohan G (D4rkCiph3r). Source status: test; severity: high. Source dates: 2023-01-31 / 2023-02-04.

{
  "product": "macos",
  "category": "process_creation"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 6c705380877749aadda1ddd9f76b2471754565d9fd95ca428494cbf43909e72a

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: Suspicious Microsoft Office Child Process - MacOS
id: 69483748-1525-4a6c-95ca-90dc8d431b68
status: test
description: Detects suspicious child processes spawning from microsoft office suite applications such as word or excel. This could indicates malicious macro execution
references:
    - https://redcanary.com/blog/applescript/
    - https://objective-see.org/blog/blog_0x4B.html
author: Sohan G (D4rkCiph3r)
date: 2023-01-31
modified: 2023-02-04
tags:
    - attack.execution
    - attack.persistence
    - attack.t1059.002
    - attack.t1137.002
    - attack.t1204.002
logsource:
    product: macos
    category: process_creation
detection:
    selection:
        ParentImage|contains:
            - 'Microsoft Word'
            - 'Microsoft Excel'
            - 'Microsoft PowerPoint'
            - 'Microsoft OneNote'
        Image|endswith:
            - '/bash'
            - '/curl'
            - '/dash'
            - '/fish'
            - '/osacompile'
            - '/osascript'
            - '/sh'
            - '/zsh'
            - '/python'
            - '/python3'
            - '/wget'
    condition: selection
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://redcanary.com/blog/applescript/
• https://objective-see.org/blog/blog_0x4B.html