Sigma Rule Library

Use Short Name Path in Command Line

Detects the use of short name paths (8.3 format) in command lines, which can be used to obfuscate paths or access restricted locations. Windows creates short 8.3 filenames (like PROGRA~1) for compatibility with MS-DOS-based or 16-bit Windows programs. When investigating, examine: - Commands using short paths to access sensitive directories or files - Web servers on Windows (especially Apache) where short filenames could bypass security controls - Correlation with other suspicious behaviors - baseline of short name usage in your environment and look for deviations

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Detection logic

selection

CommandLine|contains:
  - ~1\
  - ~2\

filter_main_system_process

ParentImage:
  - C:\Windows\System32\Dism.exe
  - C:\Windows\System32\cleanmgr.exe

filter_main_winget

- ParentImage|endswith: \winget.exe
- ParentImage|contains: \AppData\Local\Temp\WinGet\

filter_main_csc

ParentImage|startswith: C:\Windows\Microsoft.NET\Framework64\v
ParentImage|endswith: \csc.exe

filter_main_installers

- Image|contains|all:
    - \AppData\
    - \Temp\
- CommandLine|contains: \AppData\Local\Temp\

filter_optional_dopus

ParentImage: C:\Program Files\GPSoftware\Directory Opus\dopus.exe

filter_optional_aurora

ParentImage|endswith:
  - \aurora-agent-64.exe
  - \aurora-agent.exe

filter_optional_thor

ParentImage|endswith: \thor\thor64.exe

filter_optional_git

CommandLine|contains:
  - C:\Program Files\Git\post-install.bat
  - C:\Program Files\Git\cmd\scalar.exe

filter_optional_webex

- ParentImage|endswith: \WebEx\webexhost.exe
- CommandLine|contains: \appdata\local\webex\webex64\meetings\wbxreport.exe

filter_optional_veeam

ParentImage|endswith: \veeam.backup.shell.exe

filter_optional_everything

ParentImage|endswith: \Everything\Everything.exe

Condition

selection and not 1 of filter_main_* and not 1 of filter_optional_*

Raw YAML

title: Use Short Name Path in Command Line
id: 349d891d-fef0-4fe4-bc53-eee623a15969
related:
    - id: a96970af-f126-420d-90e1-d37bf25e50e1
      type: similar
status: test
description: |
    Detects the use of short name paths (8.3 format) in command lines, which can be used to obfuscate paths or access restricted locations.
    Windows creates short 8.3 filenames (like PROGRA~1) for compatibility with MS-DOS-based or 16-bit Windows programs.
    When investigating, examine:
    - Commands using short paths to access sensitive directories or files
    - Web servers on Windows (especially Apache) where short filenames could bypass security controls
    - Correlation with other suspicious behaviors
    - baseline of short name usage in your environment and look for deviations
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: 2025-10-22
tags:
    - attack.stealth
    - attack.t1564.004
    - detection.threat-hunting
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains:
            - '~1\'
            - '~2\'
    filter_main_system_process:
        ParentImage:
            - 'C:\Windows\System32\Dism.exe'
            - 'C:\Windows\System32\cleanmgr.exe'
    filter_main_winget:
        - ParentImage|endswith: '\winget.exe'
        - ParentImage|contains: '\AppData\Local\Temp\WinGet\'
    filter_main_csc:
        ParentImage|startswith: 'C:\Windows\Microsoft.NET\Framework64\v'
        ParentImage|endswith: '\csc.exe'
    filter_main_installers:
        - Image|contains|all:
              - '\AppData\'
              - '\Temp\'
        - CommandLine|contains: '\AppData\Local\Temp\' # sometimes installers spawn other installers from temp folder
    filter_optional_dopus:
        ParentImage: 'C:\Program Files\GPSoftware\Directory Opus\dopus.exe'
    filter_optional_aurora:
        ParentImage|endswith:
            - '\aurora-agent-64.exe'
            - '\aurora-agent.exe'
    filter_optional_thor:
        ParentImage|endswith: '\thor\thor64.exe'
    filter_optional_git:
        CommandLine|contains:
            - 'C:\Program Files\Git\post-install.bat'
            - 'C:\Program Files\Git\cmd\scalar.exe'
    filter_optional_webex:
        - ParentImage|endswith: '\WebEx\webexhost.exe'
        - CommandLine|contains: '\appdata\local\webex\webex64\meetings\wbxreport.exe'
    filter_optional_veeam:
        ParentImage|endswith: '\veeam.backup.shell.exe'
    filter_optional_everything:
        ParentImage|endswith: '\Everything\Everything.exe'
    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

False positives

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

References

Similar rules