Scareware
Fake security alerts — pop-ups, browser warnings, or audio alarms — designed to panic users into calling a fraudulent number or buying bogus software.
Also known as: fake virus alert, fake security pop-up
Last reviewed: 1 June 2026
Scareware uses alarming-looking warnings — 'YOUR COMPUTER IS INFECTED WITH 5 VIRUSES', 'YOUR BANK DETAILS HAVE BEEN STOLEN' — to frighten users into taking immediate, panicked action. The goal is either to sell fake antivirus software (that does nothing useful), to direct the user to a phone number where a tech-support scammer waits, or to trick them into installing actual malware under the guise of a 'fix'.
Scareware pop-ups often play audio alerts and prevent the browser being closed easily. They typically appear on compromised websites or through malvertising. They are not genuine operating-system messages — real Windows or macOS security warnings look nothing like these pop-ups.
If you encounter a scareware pop-up, force-closing the browser (via Task Manager or Activity Monitor) and running a genuine security scan from your installed antivirus is the correct response. Never call the number displayed.
Examples
- A browser pop-up fills the screen with red text saying 'CRITICAL ALERT — Your computer is locked due to suspicious activity. Call Microsoft Support immediately.' with a phone number.
Sources
- FTC — Tech Support Scams — Federal Trade Commission
- CISA — Avoiding Social Engineering and Phishing Attacks — Cybersecurity and Infrastructure Security Agency
- FCC — Frauds, Scams and Alerts Guides — Federal Communications Commission
- AARP — Fraud Watch Network — AARP