A loud warning appears on your screen: your computer is infected, call this number now. Before you do anything, here is how to tell what you are looking at.
Most of these are fake alerts
Many of these warnings are not coming from your computer at all. They are web pages made to look like a security alert, so they can scare you into calling a number, paying, or letting a stranger control your computer. A real problem can look similar, which is why it is worth checking rather than guessing.
Signs it is a fake browser alert
- It appears inside your web browser, often full screen, rather than from security software you installed.
- It tells you to call a phone number.
- It plays sounds, flashes, or shows a countdown.
- It asks for payment, especially gift cards, or asks you to let someone connect to your computer.
What to do
- Do not call the number, and do not click inside the alert.
- Close the browser. If it will not close, restart the computer. If the browser offers to restore your previous tabs, say no.
- Do not pay, and do not let anyone who contacted you, or whose number came from the alert, connect to your computer.
If you already called or paid
Do not feel embarrassed; it happens to many people. Contact your bank or card company right away. From a different, trusted device, change the passwords for accounts you may have used. Then get your computer checked.
When it might be real
A computer that is suddenly slow, shows programs you do not recognize, keeps sending your browser to pages you did not choose, or has security software that was turned off may have a real problem. A fake alert and real malware are different problems with different fixes.
If you are not sure, request an appointment and bring the computer in. I will tell you what I find before anything is done. More about virus removal.