Detection rules › Sigma
Office Macro File Download
Detects the creation of a new office macro files on the system via an application (browser, mail client). This can help identify potential malicious activity, such as the download of macro-enabled documents that could be used for exploitation.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1566.001 Phishing: Spearphishing Attachment |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 11 | FileCreate |
Rule body yaml
title: Office Macro File Download
id: 0e29e3a7-1ad8-40aa-b691-9f82ecd33d66
related:
- id: 91174a41-dc8f-401b-be89-7bfc140612a0
type: similar
status: test
description: |
Detects the creation of a new office macro files on the system via an application (browser, mail client).
This can help identify potential malicious activity, such as the download of macro-enabled documents that could be used for exploitation.
references:
- 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: Nasreddine Bencherchali (Nextron Systems)
date: 2022-01-23
modified: 2025-10-29
tags:
- attack.initial-access
- attack.t1566.001
logsource:
category: file_event
product: windows
detection:
selection_processes:
Image|endswith:
# Email clients
- '\RuntimeBroker.exe' # Windows Email clients uses RuntimeBroker to create the files
- '\outlook.exe'
- '\thunderbird.exe'
# Browsers
- '\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:
- Legitimate macro files downloaded from the internet
- Legitimate macro files sent as attachments via emails
level: low
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_processes
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'
Stage 2: selection_ext
selection_ext:
- TargetFilename|endswith:
- '.docm'
- '.dotm'
- '.xlsm'
- '.xltm'
- '.potm'
- '.pptm'
- TargetFilename|contains:
- '.docm:Zone'
- '.dotm:Zone'
- '.xlsm:Zone'
- '.xltm:Zone'
- '.potm:Zone'
- '.pptm:Zone'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Image | ends_with |
|
TargetFilename | ends_with |
|
TargetFilename | match |
|