Windows Process Creation: IExpress.exe Creating Self-Extracting Packages

Identifies IExpress.exe usage to generate self-extracting packages, including makecab.exe involvement and IExpress command-line patterns.

FreeReviewedSigma · Medium · v5
Product
windows
Category
process_creation
Author
Joseliyo Sanchez, @Joseliyo_Jstnk (SigmaHQ), DRL 1.1
Published
2024-02-05
Updated
2026-07-31
title: "Windows Process Creation: IExpress.exe Creating Self-Extracting Packages"
id: 76762cfb-1d99-43ae-b969-c6e040bd3791
status: test
description: This rule identifies Windows executions where iexpress.exe is used to create self-extracting packages, based on process relationships and specific command-line patterns. Attackers may leverage iexpress to compile or package content for execution, making it important to review the exact invocation parameters and any referenced build files. It relies on process creation telemetry, including parent image, process image/original filename, and the iexpress command line (notably the presence of ' /n ').
references:
  - https://strontic.github.io/xcyclopedia/library/iexpress.exe-D594B2A33EFAFD0EABF09E3FDC05FCEA.html
  - https://en.wikipedia.org/wiki/IExpress
  - https://decoded.avast.io/janvojtesek/raspberry-robins-roshtyak-a-little-lesson-in-trickery/
  - https://www.virustotal.com/gui/file/602f4ae507fa8de57ada079adff25a6c2a899bd25cd092d0af7e62cdb619c93c/behavior
  - https://github.com/SigmaHQ/sigma/blob/master/rules-threat-hunting/windows/process_creation/proc_creation_win_iexpress_execution.yml
author: Joseliyo Sanchez, @Joseliyo_Jstnk, Huntrule Team
date: 2024-02-05
tags:
  - attack.stealth
  - attack.t1218
  - detection.threat-hunting
logsource:
  category: process_creation
  product: windows
detection:
  selection_1_parent:
    ParentImage|endswith: \iexpress.exe
  selection_1_img:
    - Image|endswith: \makecab.exe
    - OriginalFileName: makecab.exe
  selection_2_img:
    - Image|endswith: \iexpress.exe
    - OriginalFileName: IEXPRESS.exe
  selection_2_cli:
    CommandLine|contains: " /n "
  condition: all of selection_1_* or all of selection_2_*
falsepositives:
  - Administrators building packages using iexpress.exe
level: medium
license: DRL-1.1
related:
  - id: c2b478fc-09bf-40b2-8768-ab3ec8d61c9a
    type: derived