Windows WWlib.DLL sideloading via Office process loading behavior

Alert on Windows image-load events where winword-associated processes load wwlib.dll outside expected Office paths.

FreeReviewedSigma · Medium · v2

Product: windows
Category: image_load
Author: X__Junior (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2023-05-18
Updated: 2026-07-31

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1574.001DLL
Persistence
- T1574.001DLL
Priv Esc
- T1574.001DLL
Defense Evasion
- T1574.001DLL
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags Windows image loads where a module named "wwlib.dll" is loaded, which can indicate DLL sideloading or related execution abuses. Attackers may place or induce loading of a malicious DLL under locations that legitimate applications search, leveraging Office process behavior for stealth. Telemetry relies on Windows image load events that include the loaded module path and the loading process image path.

Reporting behind it

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Windows WWlib.DLL sideloading via Office process loading behavior

Pivot detection · T1574.001 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

windows-dll-sideloading-imageloaded-wwlib-dll-associated-with-winword-e2e01011

title: Windows WWlib.DLL sideloading via Office process loading behavior
id: 8abe153c-e537-4282-8b0d-5c6a8221b794
status: test
description: This rule flags Windows image loads where a module named "wwlib.dll" is loaded, which can indicate DLL sideloading or related execution abuses. Attackers may place or induce loading of a malicious DLL under locations that legitimate applications search, leveraging Office process behavior for stealth. Telemetry relies on Windows image load events that include the loaded module path and the loading process image path.
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/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/image_load/image_load_side_load_wwlib.yml
author: X__Junior (Nextron Systems), Huntrule Team
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
license: DRL-1.1
related:
  - id: e2e01011-5910-4267-9c3b-4149ed5479cf
    type: derived

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