Windows: ie4uinit.exe Used from Non-Standard Current Directory

Flags ie4uinit.exe runs whose CurrentDirectory is outside expected system paths, indicating potential LOLBIN misuse.

FreeReviewedSigma · Medium · v2
Product
windows
Category
process_creation
Author
frack113 (SigmaHQ), DRL 1.1
Published
2022-05-07
Updated
2026-07-31
title: "Windows: ie4uinit.exe Used from Non-Standard Current Directory"
id: 8b72843b-1ec3-4484-8255-8c7b6de76eae
status: test
description: Detects execution of ie4uinit.exe (or binaries with OriginalFileName IE4UINIT.EXE) when the process current directory is not a typical Windows system path. Attackers can abuse this signed living-off-the-land binary to run actions using a prepared ie4uinit.inf from an unexpected location. The rule relies on Windows process creation telemetry, specifically the executable name and the process current directory.
references:
  - https://lolbas-project.github.io/lolbas/Binaries/Ie4uinit/
  - https://bohops.com/2018/03/10/leveraging-inf-sct-fetch-execute-techniques-for-bypass-evasion-persistence-part-2/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_lolbin_ie4uinit.yml
author: frack113, Huntrule Team
date: 2022-05-07
modified: 2022-05-16
tags:
  - attack.stealth
  - attack.t1218
logsource:
  product: windows
  category: process_creation
detection:
  lolbin:
    - Image|endswith: \ie4uinit.exe
    - OriginalFileName: IE4UINIT.EXE
  filter_correct:
    CurrentDirectory:
      - c:\windows\system32\
      - c:\windows\sysWOW64\
  filter_missing:
    CurrentDirectory: null
  condition: lolbin and not 1 of filter_*
falsepositives:
  - ViberPC updater calls this binary with the following commandline "ie4uinit.exe -ClearIconCache"
level: medium
license: DRL-1.1
related:
  - id: d3bf399f-b0cf-4250-8bb4-dfc192ab81dc
    type: derived