Real Tech Support Alert vs Scareware Popup
How to distinguish a genuine operating-system security alert from scareware designed to frighten you into calling a fake support line.
Last reviewed: 1 June 2026
Real security alerts from your operating system or antivirus software are controlled, calm, and never lock your computer until you call a phone number. Scareware popups — typically triggered by a rogue website or ad — mimic official alerts and blare alarms to stampede you into calling a fake support line that charges hundreds to 'fix' a problem that does not exist.
Side-by-side comparison
| Real OS or antivirus alert | Scareware browser popup | |
|---|---|---|
| Origin | Comes from your installed OS or antivirus software — not a browser tab | Appears inside your browser on a website you visited; cannot be scrolled past |
| Computer state | Computer continues to function normally; alert has a close or dismiss button | Claims the computer is locked, infected, or sending data; may play an alarm sound |
| Phone number | Microsoft, Apple, and security vendors do not put a phone number in an on-screen alert for you to call them | Displays a phone number prominently and urges you to call 'Microsoft Support' or 'Apple Security' |
| Action requested | Prompts you to update, scan, or quarantine — actions you take within the software | Insists you call a number or allow remote access to 'clean' the infection |
| Closing behaviour | Can be closed through normal window controls or task manager | Attempts to prevent closing; F11 or Alt+F4 may appear blocked or trigger another popup |
| Cost | Free security updates from your OS and legitimate antivirus you already own | Technician on the phone charges for 'cleaning tools', gift cards, or a support contract |
Common red flags
- Alert appears in a browser window, not a native OS dialog
- Plays an alarm sound or announces your computer is sending data
- Shows a phone number to call immediately
- Prevents you from closing the browser normally
- Claims to be from Microsoft, Apple, or a named antivirus via a website
Verification steps
- Press Alt+F4 (Windows) or Command+W (Mac) to close the browser tab
- If the browser is locked, open Task Manager and end the browser process — this is always safe
- Run a scan with your actual installed antivirus after closing the page
- Check your OS notification centre — genuine alerts appear there, not in a browser
What not to do
- Do not call the number displayed in a browser popup
- Do not allow remote access to anyone who contacted you because of a browser alert
- Do not pay for 'cleaning' services offered over the phone after a browser warning
A safe response
Close the browser — by force if necessary. Your computer is not locked and no data is being stolen just because a browser page says so. Run your real antivirus afterwards for peace of mind.
Frequently asked questions
Can a website actually lock my computer?
Websites can make browsers appear full-screen and unresponsive, but they cannot truly lock your computer. Task Manager (Windows) or Force Quit (Mac) will always let you close the browser.
What if I already called the number?
If you gave remote access to your computer, disconnect from the internet immediately and run a full antivirus scan. If you paid, contact your bank to dispute the charge. Change any passwords that may have been visible during the session.