Detection rules › Sigma
Microsoft Word Add-In Loaded
Detects Microsoft Word loading an Add-In (.wll) file which can be used by threat actors for initial access or persistence.
Known false positives
- The rules is only looking for ".wll" loads. So some false positives are expected with legitimate and allowed WLLs.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 7: Image loaded |
Rule body
title: Microsoft Word Add-In Loaded
id: 1337afba-d17d-4d23-bd55-29b927603b30
status: test
description: |
Detects Microsoft Word loading an Add-In (.wll) file which can be used by threat actors for initial access or persistence.
references:
- https://labs.withsecure.com/publications/add-in-opportunities-for-office-persistence
- https://nored0x.github.io/red-teaming/office-persistence/#what-is-a-wll-file
author: Steffen Rogge (dr0pd34d)
date: 2024-07-10
tags:
- attack.execution
- attack.t1204.002
- detection.threat-hunting
logsource:
category: image_load
product: windows
detection:
selection:
Image|endswith: '\winword.exe'
ImageLoaded|endswith: '.wll'
condition: selection
falsepositives:
- The rules is only looking for ".wll" loads. So some false positives are expected with legitimate and allowed WLLs.
level: low
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
Image|endswith: '\winword.exe'
ImageLoaded|endswith: '.wll'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Image | ends_with |
| field:"Image" kind:ends_with value:"\winword.exe" |
ImageLoaded | ends_with |
| field:"ImageLoaded" kind:ends_with value:".wll" |