Suspicious ClickFix/FileFix Execution Pattern

Description

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.

Query · sigma

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_*

Known false positives

  • Unlikely
Raw source Suspicious ClickFix/FileFix Execution Pattern · Sigma
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Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified. 
title: Suspicious ClickFix/FileFix Execution Pattern
id: d487ed4a-fd24-436d-a0b2-f4e95f7b2635
related:
    - id: f5fe36cf-f1ec-4c23-903d-09a3110f6bbb
      type: similar
status: experimental
description: |
    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.
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/ # filefix variant
author: montysecurity, Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-11-19
tags:
    - attack.execution
    - attack.t1204.001
    - attack.t1204.004
logsource:
    category: process_creation
    product: windows
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_*
falsepositives:
    - Unlikely
level: high

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