Online Safety · 5 min read
How to Recognise Fake Antivirus Websites and Scareware
Scareware is advertising that pretends to be your operating system. It is one of the oldest tricks online and it still works, because it exploits urgency rather than a software vulnerability.
Published 2026-08-09 · Last updated 2026-08-09
The tells
A web page cannot scan your computer. Any site displaying a progress bar 'scanning' your drives, naming a specific number of infections, imitating Windows dialogs inside a browser window, or showing a countdown before your files are 'deleted' is fabricating all of it.
- A website claiming to have scanned your PC
- Fake Windows or macOS dialog boxes inside the browser
- A specific invented infection count
- Countdown timers and forced full-screen mode
- A phone number for 'Microsoft support'
How to close it safely
Do not click anything inside the page, including the X. Use Alt+F4, or open Task Manager with Ctrl+Shift+Esc and end the browser process. When reopening the browser, decline the offer to restore the previous session.
Never call the number
Tech-support scams exist to get remote access to your machine and a payment. No legitimate vendor puts an emergency phone number in a browser pop-up. If you already granted remote access, disconnect the machine, run a full offline scan and change your passwords from a different device.
Frequently asked questions
- Can a website really detect a virus on my PC?
- No. A browser page has no access to your file system. Any such claim is a scam.
- I clicked the pop-up — what now?
- Close the browser via Task Manager, run a full scan plus the free Malwarebytes scanner, remove unfamiliar extensions and change passwords if you entered any.