Sigma rule: Potential ClickFix Execution Pattern - Registry

Rule

Title

Potential ClickFix Execution Pattern - Registry

Status

experimental

Level

high

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-03-25

Modified

2025-11-19

File

rules/windows/registry/registry_set/registry_set_potential_clickfix_execution.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

windows

category

registry_set

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_*

False positives (as the rule lists them)

• Legitimate applications using RunMRU with HTTP links

Tags

• attack.execution
• attack.t1204.001

MITRE ATT&CK ids this rule names

• T1204.001

Related rules

• d487ed4a-fd24-436d-a0b2-f4e95f7b2635 (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://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/

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/registry/registry_set/registry_set_potential_clickfix_execution.yml