Use Short Name Path in Image — Sigma Rule

Rule metadata and linked tags

Author: frack113, Nasreddine Bencherchali. Source status: test; severity: medium. Source dates: 2022-08-07 / 2025-10-20.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: d4aeae081230a675f4ab40e8b947566b507a7abe1d4375010d81e2bc1a7a4acc

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Use Short Name Path in Image
id: a96970af-f126-420d-90e1-d37bf25e50e1
related:
    - id: 349d891d-fef0-4fe4-bc53-eee623a15969
      type: similar
status: test
description: Detect use of the Windows 8.3 short name. Which could be used as a method to avoid Image detection
references:
    - https://www.acunetix.com/blog/articles/windows-short-8-3-filenames-web-security-problem/
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc959352(v=technet.10)
    - https://twitter.com/frack113/status/1555830623633375232
author: frack113, Nasreddine Bencherchali
date: 2022-08-07
modified: 2025-10-20
tags:
    - attack.stealth
    - attack.t1564.004
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|contains:
            - '~1\'
            - '~2\'
    filter_main_system_process:
        ParentImage:
            - 'C:\Windows\System32\Dism.exe'
            - 'C:\Windows\System32\cleanmgr.exe'  # Spawns DismHost.exe with a shortened username (if too long)
    filter_main_installers:
        - Image|contains|all:
              - '\AppData\'
              - '\Temp\'
        - Image|endswith:
              - '~1\unzip.exe'
              - '~1\7zG.exe'
    filter_optional_webex:
        ParentImage|endswith: '\WebEx\WebexHost.exe' # Spawns a shortened version of the CLI and Image processes
    filter_optional_thor:
        ParentImage|endswith: '\thor\thor64.exe'
    filter_optional_installshield:
        - Product: 'InstallShield (R)'
        - Description: 'InstallShield (R) Setup Engine'
        - Company: 'InstallShield Software Corporation'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Applications could use this notation occasionally which might generate some false positives. In that case Investigate the parent and child process.
level: medium

Original YAML and metadata in JSON

False positives

• Applications could use this notation occasionally which might generate some false positives. In that case Investigate the parent and child process.

Source references

• https://www.acunetix.com/blog/articles/windows-short-8-3-filenames-web-security-problem/
• https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc959352(v=technet.10)
• https://twitter.com/frack113/status/1555830623633375232