Microsoft Office DLL Sideload

Description

Detects DLL sideloading of DLLs that are part of Microsoft Office from non standard location

Query · sigma

selection:
  ImageLoaded|endswith: \outllib.dll
filter:
  ImageLoaded|startswith:
  - C:\Program Files\Microsoft Office\OFFICE
  - C:\Program Files (x86)\Microsoft Office\OFFICE
  - C:\Program Files\Microsoft Office\Root\OFFICE
  - C:\Program Files (x86)\Microsoft Office\Root\OFFICE
condition: selection and not filter

Known false positives

  • Unlikely
Raw source Microsoft Office DLL Sideload · Sigma
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Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified. 
title: Microsoft Office DLL Sideload
id: 829a3bdf-34da-4051-9cf4-8ed221a8ae4f
status: test
description: Detects DLL sideloading of DLLs that are part of Microsoft Office from non standard location
references:
    - https://hijacklibs.net/ # For list of DLLs that could be sideloaded (search for dlls mentioned here in there)
author: Nasreddine Bencherchali (Nextron Systems), Wietze Beukema (project and research)
date: 2022-08-17
modified: 2023-03-15
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\outllib.dll'
    filter:
        ImageLoaded|startswith:
            - 'C:\Program Files\Microsoft Office\OFFICE'
            - 'C:\Program Files (x86)\Microsoft Office\OFFICE'
            - 'C:\Program Files\Microsoft Office\Root\OFFICE'
            - 'C:\Program Files (x86)\Microsoft Office\Root\OFFICE'
    condition: selection and not filter
falsepositives:
    - Unlikely
level: high

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