Possible Office Macro File Download (via file_event)

title: Possible Office Macro File Download (via file_event)
id: 78a24459-4898-5588-aa25-a9d1a041f42d
status: stable
description: This rule detects the creation of a new office macro files on the system via an application (browser, mail client). This can help identify potential hostile activity, such as the download of macro-enabled documents that could be used for exploitation.
references:
    - https://attack.mitre.org/techniques/T1566/001/
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1566.001/T1566.001.md
    - https://learn.microsoft.com/en-us/deployoffice/compat/office-file-format-reference
author: Huntrule Team
date: 2026-03-25
tags:
    - attack.initial-access
    - attack.t1566.001
logsource:
    category: file_event
    product: windows
detection:
    selection_processes:
        Image|endswith:
            - '\RuntimeBroker.exe'
            - '\outlook.exe'
            - '\thunderbird.exe'
            - '\brave.exe'
            - '\chrome.exe'
            - '\firefox.exe'
            - '\iexplore.exe'
            - '\maxthon.exe'
            - '\MicrosoftEdge.exe'
            - '\msedge.exe'
            - '\msedgewebview2.exe'
            - '\opera.exe'
            - '\safari.exe'
            - '\seamonkey.exe'
            - '\vivaldi.exe'
            - '\whale.exe'
    selection_ext:
        - TargetFilename|endswith:
              - '.docm'
              - '.dotm'
              - '.xlsm'
              - '.xltm'
              - '.potm'
              - '.pptm'
        - TargetFilename|contains:
              - '.docm:Zone'
              - '.dotm:Zone'
              - '.xlsm:Zone'
              - '.xltm:Zone'
              - '.potm:Zone'
              - '.pptm:Zone'
    condition: all of selection_*
falsepositives:
    - Unknown
level: low