Detection rules › Sigma
Self Extracting Package Creation Via Iexpress.EXE From Potentially Suspicious Location
Detects the use of iexpress.exe to create binaries via Self Extraction Directive (SED) files located in potentially suspicious locations. This behavior has been observed in-the-wild by different threat actors.
Known false positives
- Administrators building packages using iexpress.exe
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
title: Self Extracting Package Creation Via Iexpress.EXE From Potentially Suspicious Location
id: b2b048b0-7857-4380-b0fb-d3f0ab820b71
status: test
description: |
Detects the use of iexpress.exe to create binaries via Self Extraction Directive (SED) files located in potentially suspicious locations.
This behavior has been observed in-the-wild by different threat actors.
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
author: Joseliyo Sanchez, @Joseliyo_Jstnk, Nasreddine Bencherchali (Nextron Systems)
date: 2024-02-05
modified: 2024-06-04
tags:
- attack.stealth
- attack.t1218
logsource:
category: process_creation
product: windows
detection:
# VT Query: behavior_processes:"iexpress.exe" and behavior_processes:"/n /q /m" and behavior_processes:"*.sed*" and p:5+
selection_img:
- Image|endswith: '\iexpress.exe'
- OriginalFileName: 'IEXPRESS.exe'
selection_cli:
CommandLine|contains|windash: ' /n '
selection_paths:
CommandLine|contains:
# Note: Add more uncommon paths that fit your organizational needs.
- ':\ProgramData\'
- ':\Temp\'
- ':\Windows\System32\Tasks\'
- ':\Windows\Tasks\'
- ':\Windows\Temp\'
- '\AppData\Local\Temp\'
condition: all of selection_*
falsepositives:
- Administrators building packages using iexpress.exe
level: high
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
- Image|endswith: '\iexpress.exe'
- OriginalFileName: 'IEXPRESS.exe'
Stage 2: selection_cli
selection_cli:
CommandLine|contains|windash: ' /n '
Stage 3: selection_paths
selection_paths:
CommandLine|contains:
- ':\ProgramData\'
- ':\Temp\'
- ':\Windows\System32\Tasks\'
- ':\Windows\Tasks\'
- ':\Windows\Temp\'
- '\AppData\Local\Temp\'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
Image | ends_with |
| field:"Image" kind:ends_with value:"\iexpress.exe" |
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"IEXPRESS.exe" |