Microsoft Office DLL Sideload

SIGMA detection rule by Nasreddine Bencherchali (Nextron Systems), Wietze Beukema (project and research) · NOASSERTION

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

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

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

c3ead94a-02aa-42a8-ad1f-88e9c1097480

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

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