Detection rules › Sigma

Potential WWlib.DLL Sideloading

Status
test
Severity
medium
Log source
category image_load, product windows
Author
X__Junior (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects potential DLL sideloading of "wwlib.dll"

MITRE ATT&CK coverage

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 7: Image loaded

Rule body

title: Potential WWlib.DLL Sideloading
id: e2e01011-5910-4267-9c3b-4149ed5479cf
status: test
description: Detects potential DLL sideloading of "wwlib.dll"
references:
    - https://twitter.com/WhichbufferArda/status/1658829954182774784
    - https://news.sophos.com/en-us/2022/11/03/family-tree-dll-sideloading-cases-may-be-related/
    - https://securelist.com/apt-luminousmoth/103332/
author: X__Junior (Nextron Systems)
date: 2023-05-18
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\wwlib.dll'
    filter_main_path:
        Image|startswith:
            - 'C:\Program Files (x86)\Microsoft Office\'
            - 'C:\Program Files\Microsoft Office\'
        Image|endswith: '\winword.exe'
        ImageLoaded|startswith:
            - 'C:\Program Files (x86)\Microsoft Office\'
            - 'C:\Program Files\Microsoft Office\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    ImageLoaded|endswith: '\wwlib.dll'

Stage 2: not filter_main_path

filter_main_path:
    Image|startswith:
        - 'C:\Program Files (x86)\Microsoft Office\'
        - 'C:\Program Files\Microsoft Office\'
    Image|endswith: '\winword.exe'
    ImageLoaded|startswith:
        - 'C:\Program Files (x86)\Microsoft Office\'
        - 'C:\Program Files\Microsoft Office\'

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Imagestarts_withC:\Program Files (x86)\Microsoft Office\excludes:Image field:"Image" value:"C:\Program Files (x86)\Microsoft Office\"
Imagestarts_withC:\Program Files\Microsoft Office\excludes:Image field:"Image" value:"C:\Program Files\Microsoft Office\"
ImageLoadedstarts_withC:\Program Files (x86)\Microsoft Office\excludes:ImageLoaded field:"ImageLoaded" value:"C:\Program Files (x86)\Microsoft Office\"
ImageLoadedstarts_withC:\Program Files\Microsoft Office\excludes:ImageLoaded field:"ImageLoaded" value:"C:\Program Files\Microsoft Office\"
Imageends_with\winword.exeexcludes:Image field:"Image" value:"\winword.exe"

Indicators

These rows show field, operator, and value matches.