Fake Virus Warning on Your Screen: What to Do Right Now

A window takes over your screen. It says your computer is infected. There may be a siren, a recorded voice, or a warning that looks like it came from Windows or from Apple, and there is a phone number telling you to call immediately.

Here is what to do, in order, and what to do if you already called. Every step below comes from the FTC, the FBI, CISA, Microsoft or Apple. Sources are listed at the bottom.

Before you do anything

Do not call the number. Do not click anything inside the window. Do not let anyone connect to your computer. A warning that tells you to call a phone number is not a legitimate security warning. These fake warnings often come from a malicious or compromised website, and some can also be caused by malicious software.

1. Do not call the number

This is the one step that matters most, and it is the one every official source agrees on.

Real warnings never ask you to call. The FTC puts it plainly: real security pop-up warnings and messages will never ask you to call a phone number.
Microsoft does not put phone numbers in error messages. Microsoft states that genuine Microsoft error messages never include a phone number to call, and that Microsoft will never reach out to you first to offer technical support.
Apple says to ignore it. Apple’s guidance for these pop-ups is not to call the number or follow the links, and to navigate away from the page or close the window or tab.
The FBI says the same. The FBI’s Internet Crime Complaint Center advises not to contact the telephone number provided in a pop-up, text or email.

The hurry is the whole tactic. The FBI notes that criminals create a sense of urgency to produce fear and push people into acting immediately. Nothing on that screen gets worse because you took a minute.

2. Close the window without touching what is on it

Close it from outside the page rather than clicking anything inside it.

On a Windows computer

Close the browser. Microsoft’s advice for this exact situation is to close the browser immediately, and to try pressing Alt and F4 together if the mouse will not do it.
If the browser will not close, restart the computer. That is also Microsoft’s advice.
If you would rather close just the browser, Microsoft publishes these steps: right-click Start, select Task Manager, select Processes, right-click the browser in the list (Microsoft’s instructions name Microsoft Edge), select End task, then close Task Manager and reopen the browser.

On a Mac

Apple’s advice for these pop-ups is to navigate away from the page, or close the window or tab.
If the browser will not respond, Apple’s standard way to close an app that is stuck is to press Option, Command and Esc together, or choose Force Quit from the Apple menu, then select the app and click Force Quit.

The screen may look locked while all this is happening. Microsoft’s own wording is that these messages may appear to block access to your machine.

3. Work out whether anything actually happened

Seeing the message is not the same as having a problem. Microsoft says these fake error messages are usually generated by a malicious or compromised website. Apple says these pop-ups are usually fraudulent advertisements.

What matters is whether you did any of the following:

Called the number.
Let someone connect to your computer.
Installed something they told you to install.
Gave a password, a verification code, or bank or card details.
Paid them.

If none of those happened, close the warning. If it keeps returning or you are still concerned, update your security software and run a scan using the security tools already on your computer. If any of them did happen, go to the section further down.

Microsoft adds that if you suspect the pop-up was caused by malware, you should scan your device with Windows Security.

4. Know what a real warning looks like

Scary presentation is not evidence. The FTC describes these pop-ups imitating a blue error screen or trusted antivirus software, and Microsoft describes messages that fill the screen and may use alarming sounds or recorded voices.

No phone number. Real security warnings do not ask you to call. Microsoft: genuine Microsoft error messages never include a phone number.
No unsolicited contact. The FTC says legitimate tech companies will not contact you by phone, email or text to tell you there is a problem with your computer. Microsoft: if you did not ask, they will not call you.
Apple will not ask for certain things at all. Apple states it will never ask you for your password, your device passcode or your two-factor code, and will never ask you to turn off a security feature.
Firefox has no phone support. Mozilla states that it does not offer telephone support, and that you should not call or give information to anyone claiming to represent Mozilla.

5. If someone is on the phone with you now, hang up

If you already dialed and someone is talking you through something, ending the call is the right move, and you do not owe them an explanation.

Apple’s advice for an unsolicited or suspicious call from someone claiming to be Apple Support is simply to hang up.
The FBI advises never to let an unknown caller take control of your devices or accounts, and never to download software at their request.
If the call turns into someone claiming to be from a government agency: the FTC states that someone who works for the government will never tell you to move your money to protect it, never tell you to put money in a federal safety locker, and never demand payment.
Say it out loud to someone first: a spouse, an adult child, a neighbor, or your bank on its own number.
Free help by phone: the National Elder Fraud Hotline, run by the US Department of Justice, at 833-372-8311.

I already called, or let someone in. What now?

Acting quickly helps, and this happens to careful people every day. These are the steps the FTC and Microsoft recommend.

You let someone connect to your computer, or installed what they told you to install. Microsoft: uninstall any applications the scammers asked you to install, run a full scan with Windows Security, and change your passwords. Microsoft adds that if you gave them access to your device, you should consider resetting it. The FTC’s version: update your security software, run a scan, and delete anything it identifies as a problem.
You gave a password or a verification code. Change it now, and change it anywhere else you used the same one. Turn on two-factor authentication where it is offered.
You paid. Contact whoever moved the money straight away and say it was a scam: your card issuer or bank on the number on the back of your card, the payment app, the wire company, or the gift card company. Ask them to refund or reverse it. Keep any gift card and its receipt.
You paid with cryptocurrency. Contact the exchange or the crypto ATM operator and tell them the transaction was fraudulent.
You gave your Social Security number or other identity details. Go to IdentityTheft.gov and answer the questions. It builds a recovery plan for your situation and fills in the letters for you.
They contact you again about a refund, or say they overpaid and ask you to send some back. The FTC is direct about this one: that is always a scam.
Someone offers to get your money back. Treat it as a second scam. The FBI’s IC3 states that it will never directly contact you, and never asks for payment to recover lost funds.

Where to report it

Scams and fraud: ReportFraud.ftc.gov (Federal Trade Commission)
Identity theft: IdentityTheft.gov
Crime committed online: ic3.gov (FBI Internet Crime Complaint Center)
A scam impersonating Microsoft: Microsoft has its own reporting page for technical support scams.
If you mailed cash: US Postal Inspection Service, 1-877-876-2455
If you would rather talk to a person: National Elder Fraud Hotline, 833-372-8311

Reporting does not always bring money back, but it helps investigators spot patterns, and it costs nothing.

Remember this

Do not call. Close it from outside. Then check.

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Sources

Checked against these official sources on September 22, 2026:

This page is general information, not legal or financial advice.