Potential ClickFix Execution Pattern

01

description

What this is, in brief.

Detects potential ClickFix malware execution patterns by monitoring registry modifications in RunMRU keys containing HTTP/HTTPS links. ClickFix is known to be distributed through phishing campaigns and uses techniques like clipboard hijacking and fake CAPTCHA pages. Through the fakecaptcha pages, the adversary tricks users into opening the Run dialog box and pasting clipboard-hijacked content, such as one-liners that execute remotely hosted malicious files or scripts.

02

rule source (YAML)

title: Potential ClickFix Execution Pattern - Registry
id: f5fe36cf-f1ec-4c23-903d-09a3110f6bbb
related:
    - id: d487ed4a-fd24-436d-a0b2-f4e95f7b2635
      type: similar
status: experimental
description: |
    Detects potential ClickFix malware execution patterns by monitoring registry modifications in RunMRU keys containing HTTP/HTTPS links.
    ClickFix is known to be distributed through phishing campaigns and uses techniques like clipboard hijacking and fake CAPTCHA pages.
    Through the fakecaptcha pages, the adversary tricks users into opening the Run dialog box and pasting clipboard-hijacked content,
    such as one-liners that execute remotely hosted malicious files or scripts.
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://medium.com/@boutnaru/the-windows-foreniscs-journey-run-mru-run-dialog-box-most-recently-used-57375a02d724
    - https://unit42.paloaltonetworks.com/preventing-clickfix-attack-vector/
    - https://medium.com/@poudelswachchhanda123/preventing-lnk-and-fakecaptcha-threats-a-system-hardening-approach-2f7b7ed2e493
    - https://www.scpx.com.au/2025/11/16/decades-old-finger-protocol-abused-in-clickfix-malware-attacks/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-03-25
modified: 2025-11-19
tags:
    - attack.execution
    - attack.t1204.001
logsource:
    category: registry_set
    product: windows
detection:
    selection_registry:
        TargetObject|contains: '\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\RunMRU\'
    selection_details:
        Details|contains:
            - 'http://'
            - 'https://'
    selection_susp_pattern:
        - Details|contains:
              # Add more suspicious keywords
              - 'account'
              - 'anti-bot'
              - 'botcheck'
              - 'captcha'
              - 'challenge'
              - 'confirmation'
              - 'fraud'
              - 'human'
              - 'identification'
              - 'identificator'
              - 'identity'
              - 'robot'
              - 'validation'
              - 'verification'
              - 'verify'
        - Details|contains:
              - '%comspec%'
              - 'bitsadmin'
              - 'certutil'
              - 'cmd'
              - 'cscript'
              - 'curl'
              - 'finger'
              - 'mshta'
              - 'powershell'
              - 'pwsh'
              - 'regsvr32'
              - 'rundll32'
              - 'schtasks'
              - 'wget'
              - 'wscript'
    condition: all of selection_*
falsepositives:
    - Legitimate applications using RunMRU with HTTP links
level: high

04

detects techniques (1)

ATT&CK techniques this enables or maps to.

T1204.001Malicious Link

05

references

External citations — patches, advisories, analysis.