Potentially Suspicious Cabinet File Expansion (via process_creation)

This rule detects the expansion or decompression of cabinet files from potentially anomalous or uncommon locations, e.g. seen in Iranian MeteorExpress related attacks

SigmamediumWindowsv1
sigma
title: Potentially Suspicious Cabinet File Expansion (via process_creation)
id: 0f94a1a8-a2ed-5223-8734-ba40158f3d05
status: stable
description: This rule detects the expansion or decompression of cabinet files from potentially anomalous or uncommon locations, e.g. seen in Iranian MeteorExpress related attacks
references:
    - https://attack.mitre.org/techniques/T1218/
    - https://labs.sentinelone.com/meteorexpress-mysterious-wiper-paralyzes-iranian-trains-with-epic-troll
    - https://blog.malwarebytes.com/threat-intelligence/2021/08/new-variant-of-konni-malware-used-in-campaign-targetting-russia/
author: Huntrule Team
date: 2026-06-12
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_cmd:
        Image|endswith: '\expand.exe'
        CommandLine|contains|windash: '-F:'
    selection_folders_1:
        CommandLine|contains:
            - ':\Perflogs\'
            - ':\ProgramData'
            - ':\Users\Public\'
            - ':\Windows\Temp\'
            - '\Admin$\'
            - '\AppData\Local\Temp\'
            - '\AppData\Roaming\'
            - '\C$\'
            - '\Temporary Internet'
    selection_folders_2:
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Favorites\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Favourites\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Contacts\'
    filter_optional_dell:
        ParentImage: 'C:\Program Files (x86)\Dell\UpdateService\ServiceShell.exe'
        CommandLine|contains: 'C:\ProgramData\Dell\UpdateService\Temp\'
    condition: selection_cmd and 1 of selection_folders_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium

Known false positives

  • Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.