Detection rules › Sigma
Suspicious ClickFix/FileFix Execution Pattern
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1204.001 User Execution: Malicious Link, T1204.004 User Execution: Malicious Copy and Paste |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
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
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_parent
selection_parent:
ParentImage|endswith: '\explorer.exe'
CommandLine|contains: '#'
Stage 2: selection_cli_captcha
selection_cli_captcha:
CommandLine|contains:
- 'account'
- 'anti-bot'
- 'botcheck'
- 'captcha'
- 'challenge'
- 'confirmation'
- 'fraud'
- 'human'
- 'identification'
- 'identificator'
- 'identity'
- 'robot'
- 'validation'
- 'verification'
- 'verify'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
CommandLine | match |
|
ParentImage | ends_with |
|