Forget Everything You Know About Ransomware
Well, don’t do that exactly, but keep this in mind:
Interlock ransomware doesn’t necessarily arrive in your inbox disguised as a fake invoice or urgent payment request.
This threat lurks on legitimate websites that have been secretly compromised (like an attack that compromised over 100 car dealership websites in April), emails with links that take you to a page displaying a “Captcha” (such as one that impersonated Booking.com), or through “malvertisements,” online ads that look like the real thing.
This threat lurks on legitimate websites that have been secretly compromised (like a supply chain attack that compromised over 100 car dealership websites in April), emails with links that take you to a page displaying a fake “Captcha” (such as one that impersonated Booking.com), or through “malvertisements,” online ads that look like the real thing.
How a ClickFix Scheme Strikes
The Setup: Criminals hack legitimate websites or create “lookalike” sites and plant invisible code.
The Hook: You visit a trusted site. A popup appears claiming your browser needs a “security update” or has an “urgent error.”
The Trap: The fake message instructs you to press Windows key + R, press Ctrl + V, and press Enter. These three keystrokes execute hidden malicious code, instantly infecting your system.
Real-World Examples of ClickFix Pop-Up Messages
”Browser Critical Error” messages on familiar websites
“Update Required Immediately” popups with manual instructions
“Fix Network Connection” prompts asking you to copy/paste commands
“Security Alert” windows requesting keyboard shortcuts instead of normal downloads
Six Guidelines to Prevent ClickFix Attacks
- Never follow keyboard instructions from popups
- Close suspicious windows immediately
- Update browsers through official channels only
- When in doubt, restart your browser
- Report suspicious sites to your IT provider
- Put preventative measures in place including MFA, firewalls, and email filtering according to CISA’s guidelines (our team can manage this process for you).
CISA issued an official warning about Interlock in July 2025. In addition to traditional email-based attacks, this targets the websites you trust most, so employee training is a crucial defense against this threat.
Interlock proves cybercriminals adapt faster than defenses. When legitimate websites become weapons, your best protection is skepticism. No real security update requires manual keyboard commands.
Need guidance with training employees or exploring advanced security options? Call us at (309) 689-3900.
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