You are reading a web page when the screen suddenly fills with a red warning. A siren sounds. A voice says your computer is infected and you must call a number immediately. It looks official, and it may even carry a Microsoft or Apple logo.
It is a scam. Nothing is wrong with your computer yet. The goal is to frighten you into calling, so that someone can talk you into paying for a fake repair or into giving them remote control of your machine.
How to tell it is fake
- It gives you a phone number to call. Real security warnings from Microsoft, Apple or your antivirus program never include a phone number.
- It appears inside your web browser. A real antivirus alert comes from the program installed on your computer, not from a web page.
- It is loud and urgent. Sirens, countdown timers and threats that your files will be deleted are pressure tactics. Real software does not behave like that.
- It will not let you close it. Scam pages go full screen and hide the close button on purpose.
- It asks for payment by gift card, wire transfer or cryptocurrency. No legitimate company does this.
How to close it safely
Do not click anything inside the warning, not even a button that says Cancel or Close.
On Windows: press Ctrl + Shift + Esc to open Task Manager, select your browser in the list, and choose End task.
On a Mac: press Command + Option + Esc, select your browser, and choose Force Quit.
If that does not work, hold the power button down until the computer turns off, then start it again.
When you reopen the browser, it may offer to restore your previous pages. Say no, or the scam page will come straight back.
If you already called the number
It happens to careful people every day. Act quickly and do not be embarrassed.
- If you let them connect to your computer, disconnect it from the internet now. Turn off Wi-Fi or unplug the network cable. Have the computer checked before you use it for anything sensitive, because they may have left software behind.
- If you paid by card, call your bank or card company immediately, say it was fraud, and ask them to dispute the charge and replace the card.
- If you gave them any passwords, or typed any while they were connected, change those passwords from a different device. Start with email and banking.
- If you paid with gift cards, contact the card issuer right away with the card numbers and receipt. Sometimes the money can be frozen.
- Expect them to call back. They often do, sometimes offering a "refund". That is the same scam again. Hang up.
In the United States you can report the scam at reportfraud.ftc.gov. Reports help investigators shut these operations down.
How to see fewer of them
- Keep your browser and operating system up to date.
- Be careful with search results for support phone numbers. Scammers buy adverts that look like the real company. Go to the company's own website instead.
- Do not allow websites to send you notifications unless you really want them. Many fake warnings arrive that way.
- Talk to the people around you about it, especially older relatives. Knowing that these warnings exist is most of the protection.
Remember
No real company will ever take over your screen and tell you to phone them. If a warning has a phone number on it, it is a scam. Close it and carry on.