Microsoft Excel Add-In Loaded

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