Windows UAC Bypass via .NET Code Profiler DLL Hijacking on mmc.exe (pe386.dll in Temp)

Flags creation of Temp\pe386.dll under a user profile, consistent with mmc/.NET code profiler UAC bypass behavior.

FreeReviewedSigma · High · v2

Product: windows
Category: file_event
Author: Christian Burkard (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2021-08-30
Updated: 2026-07-31

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1548.002Bypass User Account Control
Defense Evasion
- T1548.002Bypass User Account Control
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags file activity matching a DLL hijack pattern used for a UAC bypass chain involving .NET Code Profiler and mmc.exe. Attackers write a specific payload DLL into the current user’s Temp directory under a pe386.dll filename, relying on the presence and loadability of that DLL. Detection relies on file event telemetry capturing a target path that begins under C:\Users\ and ends with \AppData\Local\Temp\pe386.dll.

Reporting behind it

Related detections9 linkedT1548.002 — drag to rearrange

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Windows UAC Bypass via .NET Code Profiler DLL Hijacking on mmc.exe (pe386.dll in Temp)

Pivot detection · T1548.002 · 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-uac-bypass-via-net-code-profiler-and-mmc-exe-dll-write-to-temp-pe386-dll-93a19907

title: Windows UAC Bypass via .NET Code Profiler DLL Hijacking on mmc.exe (pe386.dll in Temp)
id: 3dc0230d-6fbd-4420-826a-75d7aa74bbe0
status: test
description: This rule flags file activity matching a DLL hijack pattern used for a UAC bypass chain involving .NET Code Profiler and mmc.exe. Attackers write a specific payload DLL into the current user’s Temp directory under a pe386.dll filename, relying on the presence and loadability of that DLL. Detection relies on file event telemetry capturing a target path that begins under C:\Users\ and ends with \AppData\Local\Temp\pe386.dll.
references:
  - https://github.com/hfiref0x/UACME
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/file/file_event/file_event_win_uac_bypass_dotnet_profiler.yml
author: Christian Burkard (Nextron Systems), Huntrule Team
date: 2021-08-30
modified: 2022-10-09
tags:
  - attack.privilege-escalation
  - attack.t1548.002
logsource:
  category: file_event
  product: windows
detection:
  selection:
    TargetFilename|startswith: C:\Users\
    TargetFilename|endswith: \AppData\Local\Temp\pe386.dll
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 93a19907-d4f9-4deb-9f91-aac4692776a6
    type: derived

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