Sigma rule: Potential CommandLine Obfuscation Using Unicode Characters From Suspicious Image

Rule

Title

Potential CommandLine Obfuscation Using Unicode Characters From Suspicious Image

Status

test

Level

high

Author

frack113, Florian Roth (Nextron Systems), Josh Nickels

Date

2024-09-02

Modified

2025-05-30

File

rules/windows/process_creation/proc_creation_win_susp_cli_obfuscation_unicode_img.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

windows

category

process_creation

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_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.stealth
• attack.t1027

MITRE ATT&CK ids this rule names

• T1027

Related rules

• e0552b19-5a83-4222-b141-b36184bb8d79 (similar)
• ad691d92-15f2-4181-9aa4-723c74f9ddc3 (similar)
• 2c0d2d7b-30d6-4d14-9751-7b9113042ab9 (obsolete)

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

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_susp_cli_obfuscation_unicode_img.yml