Sigma rule: Suspicious ClickFix/FileFix Execution Pattern

Rule

Title

Suspicious ClickFix/FileFix Execution Pattern

Status

experimental

Level

high

Author

montysecurity, Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-11-19

File

rules/windows/process_creation/proc_creation_win_susp_clickfix_filefix_execution.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects suspicious execution patterns where users are tricked into running malicious commands via clipboard manipulation, either through the Windows Run dialog (ClickFix) or File Explorer address bar (FileFix).
Attackers leverage social engineering campaigns—such as fake CAPTCHA challenges or urgent alerts—encouraging victims to paste clipboard contents, often executing mshta.exe, powershell.exe, or similar commands to infect systems.

Log source

product

windows

category

process_creation

Detection

selection_parent:
    ParentImage|endswith: '\explorer.exe'
    CommandLine|contains: '#'
selection_cli_captcha:
    CommandLine|contains:
        - 'account'
        - 'anti-bot'
        - 'botcheck'
        - 'captcha'
        - 'challenge'
        - 'confirmation'
        - 'fraud'
        - 'human'
        - 'identification'
        - 'identificator'
        - 'identity'
        - 'robot'
        - 'validation'
        - 'verification'
        - 'verify'
condition: all of selection_*

False positives (as the rule lists them)

• Unlikely

Tags

• attack.execution
• attack.t1204.001
• attack.t1204.004

MITRE ATT&CK ids this rule names

• T1204.001
• T1204.004

Related rules

• f5fe36cf-f1ec-4c23-903d-09a3110f6bbb (similar)

References

• https://github.com/JohnHammond/recaptcha-phish
• https://www.zscaler.com/blogs/security-research/deepseek-lure-using-captchas-spread-malware
• https://www.threatdown.com/blog/clipboard-hijacker-tries-to-install-a-trojan/
• https://app.any.run/tasks/5c16b4db-4b36-4039-a0ed-9b09abff8be2
• https://www.esentire.com/security-advisories/netsupport-rat-clickfix-distribution
• https://www.scpx.com.au/2025/11/16/decades-old-finger-protocol-abused-in-clickfix-malware-attacks/

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_clickfix_filefix_execution.yml