Detection rules › Sigma
Microsoft Excel Add-In Loaded
Detects Microsoft Excel loading an Add-In (.xll) file
Known false positives
- The rules is only looking for ".xll" loads. So some false positives are expected with legitimate and allowed XLLs
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 7: Image loaded |
Rule body
title: Microsoft Excel Add-In Loaded
id: c5f4b5cb-4c25-4249-ba91-aa03626e3185
status: test
description: Detects Microsoft Excel loading an Add-In (.xll) file
references:
- https://www.mandiant.com/resources/blog/lnk-between-browsers
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-12
tags:
- attack.execution
- attack.t1204.002
- detection.threat-hunting
logsource:
category: image_load
product: windows
detection:
selection:
Image|endswith: '\excel.exe'
ImageLoaded|endswith: '.xll'
condition: selection
falsepositives:
- The rules is only looking for ".xll" loads. So some false positives are expected with legitimate and allowed XLLs
level: low
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
Image|endswith: '\excel.exe'
ImageLoaded|endswith: '.xll'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Image | ends_with |
| field:"Image" kind:ends_with value:"\excel.exe" |
ImageLoaded | ends_with |
| field:"ImageLoaded" kind:ends_with value:".xll" |