Windows DLL Sideloading: ClassicExplorer32.dll Loaded from Unexpected Path
Alerts when ClassicExplorer32.dll is loaded from unexpected locations, suggesting possible DLL sideloading behavior.
- Product
- windows
- Category
- image_load
- Author
- frack113 (SigmaHQ), DRL 1.1
- Published
- 2022-12-13
- Updated
- 2026-07-31
ATT&CK techniques
Execution → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule identifies when ClassicExplorer32.dll is loaded but not from the expected Classic Shell installation directory under Program Files. Loading an unexpected copy of a DLL with a legitimate name can enable DLL sideloading to run attacker-controlled code while masquerading as trusted software. It relies on Windows image load telemetry, matching the DLL filename and filtering for the known installation path.
Reporting behind it
- blogs.blackberry.comhttps://blogs.blackberry.com/en/2022/12/mustang-panda-uses-the-russian-ukrainian-war-to-attack-europe-and-asia-pacific-targets
- app.any.runhttps://app.any.run/tasks/6d8cabb0-dcda-44b6-8050-28d6ce281687/
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/image_load/image_load_side_load_classicexplorer32.yml
Changelog
v2- v2Candidate ingested via manual entry.2026-07-31
- v1No 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.
title: "Windows DLL Sideloading: ClassicExplorer32.dll Loaded from Unexpected Path"
id: f3b91c9b-1a0d-4227-a5e2-03e960275199
status: test
description: This rule identifies when ClassicExplorer32.dll is loaded but not from the expected Classic Shell installation directory under Program Files. Loading an unexpected copy of a DLL with a legitimate name can enable DLL sideloading to run attacker-controlled code while masquerading as trusted software. It relies on Windows image load telemetry, matching the DLL filename and filtering for the known installation path.
references:
- https://blogs.blackberry.com/en/2022/12/mustang-panda-uses-the-russian-ukrainian-war-to-attack-europe-and-asia-pacific-targets
- https://app.any.run/tasks/6d8cabb0-dcda-44b6-8050-28d6ce281687/
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/image_load/image_load_side_load_classicexplorer32.yml
author: frack113, Huntrule Team
date: 2022-12-13
tags:
- attack.persistence
- attack.privilege-escalation
- attack.execution
- attack.stealth
- attack.t1574.001
logsource:
category: image_load
product: windows
detection:
selection_classicexplorer:
ImageLoaded|endswith: \ClassicExplorer32.dll
filter_classicexplorer:
ImageLoaded|startswith: C:\Program Files\Classic Shell\
condition: selection_classicexplorer and not filter_classicexplorer
falsepositives:
- Unknown
level: medium
license: DRL-1.1
related:
- id: caa02837-f659-466f-bca6-48bde2826ab4
type: derived