Potential CommandLine Obfuscation Using Unicode Characters From Suspicious Image

Description

Detects potential commandline obfuscation using unicode characters. Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit.

Query · sigma

selection_img:
  Image|endswith:
  - \cmd.exe
  - \cscript.exe
  - \powershell.exe
  - \powershell_ise.exe
  - \pwsh.exe
  - \wscript.exe
  OriginalFileName:
  - Cmd.EXE
  - cscript.exe
  - PowerShell.EXE
  - PowerShell_ISE.EXE
  - pwsh.dll
  - wscript.exe
selection_special_chars:
  CommandLine|contains:
  - ˣ
  - ˪
  - ˢ
  - ∕
  - ⁄
  - ―
  - —
  -  
  - ¯
  - ®
  - ¶
  - ⠀
condition: all of selection_*

Known false positives

  • Unknown
Raw source Potential CommandLine Obfuscation Using Unicode Characters From Suspicious Image · Sigma
Esc
Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified. 
title: Potential CommandLine Obfuscation Using Unicode Characters From Suspicious Image
id: 584bca0f-3608-4402-80fd-4075ff6072e3
related:
    - id: e0552b19-5a83-4222-b141-b36184bb8d79
      type: similar
    - id: ad691d92-15f2-4181-9aa4-723c74f9ddc3 # RTLO
      type: similar
    - id: 2c0d2d7b-30d6-4d14-9751-7b9113042ab9
      type: obsolete
status: test
description: |
    Detects potential commandline obfuscation using unicode characters.
    Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit.
references:
    - https://www.wietzebeukema.nl/blog/windows-command-line-obfuscation
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1027/T1027.md#atomic-test-6---dlp-evasion-via-sensitive-data-in-vba-macro-over-http
author: frack113, Florian Roth (Nextron Systems), Josh Nickels
date: 2024-09-02
modified: 2025-05-30
tags:
    - attack.stealth
    - attack.t1027
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        Image|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\powershell.exe'
            - '\powershell_ise.exe'
            - '\pwsh.exe'
            - '\wscript.exe'
        OriginalFileName:
            - 'Cmd.EXE'
            - 'cscript.exe'
            - 'PowerShell.EXE'
            - 'PowerShell_ISE.EXE'
            - 'pwsh.dll'
            - 'wscript.exe'
    selection_special_chars:
        CommandLine|contains:
            # spacing modifier letters that get auto-replaced
            - 'ˣ' # 0x02E3
            - '˪' # 0x02EA
            - 'ˢ' # 0x02E2
            # Forward slash alternatives
            - '∕' # 0x22FF
            - '⁄' # 0x206F
            # Hyphen alternatives
            - '―' # 0x2015
            - '—' # 0x2014
            # Whitespace that don't work as path separator
            - ' ' # 0x00A0
            # Other
            - '¯'
            - '®'
            - '¶'
            # Unicode whitespace characters
            - '⠀' # Braille Pattern Blank (Unicode: U+2800)
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Detection rules belong to the projects that publish them and remain under their own licenses. This site indexes and links to them; it claims no rights in them.