Windows DLL Sideloading via CCleanerDU.dll ImageLoad from CCleaner Folder

Alerts when CCleanerDU.dll is loaded, but the loading image is not CCleaner executables in standard install paths.

FreeReviewedSigma · Medium · v2
Product
windows
Category
image_load
Author
X__Junior (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2023-07-13
Updated
2026-07-31
title: Windows DLL Sideloading via CCleanerDU.dll ImageLoad from CCleaner Folder
id: f167bf79-c580-4082-b77d-b85cd02c0be6
status: test
description: This rule flags Windows image loads where a DLL named CCleanerDU.dll is loaded. It matters because DLL sideloading can be used to execute attacker-controlled code under the context of a legitimate application. The detection relies on Windows image load telemetry, matching ImageLoaded that ends with \CCleanerDU.dll and excluding cases where the parent image path indicates loading from the expected CCleaner executables within the standard installation directories.
references:
  - https://lab52.io/blog/2344-2/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/image_load/image_load_side_load_ccleaner_du.yml
author: X__Junior (Nextron Systems), Huntrule Team
date: 2023-07-13
tags:
  - attack.persistence
  - attack.privilege-escalation
  - attack.execution
  - attack.stealth
  - attack.t1574.001
logsource:
  category: image_load
  product: windows
detection:
  selection:
    ImageLoaded|endswith: \CCleanerDU.dll
  filter_main_path:
    Image|startswith:
      - C:\Program Files\CCleaner\
      - C:\Program Files (x86)\CCleaner\
    Image|endswith:
      - \CCleaner.exe
      - \CCleaner64.exe
  condition: selection and not 1 of filter_main_*
falsepositives:
  - False positives could occur from other custom installation paths. Apply additional filters accordingly.
level: medium
license: DRL-1.1
related:
  - id: 1fbc0671-5596-4e17-8682-f020a0b995dc
    type: derived