⚠️ The ClickFix JavaScript–PowerShell Attack: The Clipboard Trap You Haven’t Heard Of

Cybercriminals are getting sneaky — like, social engineering meets sleight-of-hand sneaky. Enter the ClickFix attack, a clipboard hijack that leverages JavaScript, PowerShell, and a little human psychology to deliver full-blown malware.

This attack is making the rounds right now, and if your users have ever pasted anything into the Run prompt without thinking… you’re already at risk.

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🧠 What Is the ClickFix Attack?

At its core, this is a JavaScript-to-PowerShell clipboard injection scam — where attackers trick the user into unknowingly running malicious code on their own system.

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🧪 How the Attack Works (Step-by-Step)

1. Initial Hook
   Victim clicks on a malicious ad, fake CAPTCHA page, or phishing email link — landing on a fake browser warning (e.g., “Chrome needs repair” or “Fix loading issue”).

2. Clipboard Hijack via JavaScript
   The webpage silently copies a preloaded PowerShell command to the user’s clipboard using the JavaScript Clipboard API.

3. Social Engineering Prompt
   The victim sees a helpful-looking popup:

   “To resolve this issue, press Windows + R, paste the following, and press Enter.”

4. User Executes Malware
   Without realizing it, they paste a PowerShell payload into the Run dialog that downloads and executes malware.

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🎯 Why It’s So Effective

• ✅ No file downloads or email attachments
• ✅ Bypasses traditional AV because you run the command
• ✅ Exploits user trust and reflexes (“just follow the instructions”)
• ✅ Silent — clipboard API actions don’t show any UI indicators

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💣 Common Payloads Observed

• 🐍 Lumma Stealer – steals browser cookies, autofill data, crypto wallets
• 💼 NetSupport RAT – remote access trojan disguised as legitimate software
• 🧠 DarkGate – loader capable of persistence, evasion, and further payloads
• 🧬 AsyncRAT – gives full remote control and surveillance capability
• 🎯 Havoc C2 Beacon – post-exploitation tool used by APTs

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🚨 Real-World Targets

ClickFix is actively being used against:

• Healthcare & insurance providers
• Law firms & accounting offices
• Manufacturing and logistics
• Government contractors
• Remote workers using unmanaged devices

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🔐 How to Defend Against ClickFix Attacks

🛡️ 1. Lock Down PowerShell

• Use AppLocker, WDAC, or Group Policy to restrict PowerShell execution to admins.
• Use Constrained Language Mode for non-admin users.

🛡️ 2. Browser + Clipboard Protections

• Use browser extensions that disable clipboard auto-access.
• Disable clipboard permissions for untrusted sites via browser settings or enterprise policies.

🛡️ 3. Train Your Team

• Teach users: Never paste commands from a popup or browser into the Run window.
• Include ClickFix-style simulations in phishing training.

🛡️ 4. Monitor and Alert

• Configure your EDR or SIEM to flag suspicious PowerShell behavior:
  • Clipboard reads + script execution
  • Invoke-WebRequest or IEX usage
  • Unusual use of cmd.exe /c from a user session

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🧠 Pro Tip: “Helpful” Doesn’t Mean Harmless

ClickFix preys on users who just want to solve a problem. It exploits trust, speed, and muscle memory — the same instincts that make us good at our jobs.

💬 “The most dangerous malware is the one you run yourself — willingly.”

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📋 TL;DR Summary

Feature	Danger
Uses clipboard hijack	Yes — via JavaScript Clipboard API
Requires user action	Yes — user pastes & runs PowerShell manually
Traditional AV detects	Often no — user is executing the code themselves
Mitigation	PowerShell restrictions, clipboard permissions, user training

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🧯 Response Checklist

• ✅ Disable clipboard access in browsers via policies
• ✅ Block PowerShell for non-admin users
• ✅ Implement behavior-based PowerShell detection
• ✅ Run a phishing test simulation that mimics ClickFix
• ✅ Update awareness training immediately

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🧠 Stay sharp. Stay skeptical. And never, ever paste mystery code into your system — no matter how friendly that popup looks.