Microsoft never calls you to tell you your computer has a virus. This is one of the oldest and most prevalent tech support scams. If you let them 'help,' they will install malware and steal your banking info.
About this scam type: Calls claiming your Microsoft Windows has a virus or security problem
ScamRadar verdict: scam · Risk score: 97/100
Caller: This is the Microsoft Windows Defender Security Team. Your computer has been broadcasting infection signals to our servers for 48 hours. We've detected 17 viruses and 4 Trojans actively stealing your banking information. We need to remote in immediately to remove them — please go to www.fastsupport.com and give me the 6-digit code.
Microsoft does not monitor your PC and never calls users about infections. The remote support tool (GoToAssist FastSupport, AnyDesk, TeamViewer) is the scam — once they're in, they lock your files and demand payment.
If you let them remote in, immediately disconnect from the internet (unplug ethernet, turn off Wi-Fi). Restart in safe mode and uninstall any remote support software they installed (LogMeIn, AnyDesk, TeamViewer, Supremo, FastSupport). Run a full antivirus scan with Microsoft Defender plus a second-opinion scanner like Malwarebytes. Change every important password from a different, trusted device — banking, email, social media. If you gave card or bank details, contact your bank. If they convinced you to log into your bank during the session, freeze your accounts and request new account numbers. Many tech support scams escalate to wire transfers and gift card purchases — if you sent any payment, report at reportfraud.ftc.gov and consumer.ftc.gov immediately, contact the gift card issuer or wire service for possible recovery, and file with your local police.
Microsoft does not monitor consumer PCs and does not make outbound calls about viruses, ever. Real Microsoft support is opt-in only at support.microsoft.com — you initiate every contact. Real Windows error messages never include a phone number. Pop-ups claiming to be Microsoft with a phone number are 100% fake and are part of the same scam ecosystem. If a pop-up locks your browser, force-close it (Ctrl+Shift+Esc on Windows, Cmd+Option+Esc on Mac).
Never. Microsoft does not monitor consumer PCs for infections and does not make outbound calls about computer problems. Any unsolicited call claiming to be from Microsoft, Windows Defender, or 'Microsoft Security' is a scam.
Scammers call or display fake browser pop-ups claiming your PC is infected, then convince you to install remote control software (AnyDesk, TeamViewer, FastSupport) so they can 'fix' it. Once connected, they lock your files, show fake virus reports, and demand payment by wire, gift card, or cryptocurrency.
Disconnect from the internet immediately, restart in safe mode, uninstall any remote support tools they added, run a full antivirus scan, and change every important password from a different device. If you also gave payment, contact your bank and report at reportfraud.ftc.gov.
Real Windows error messages never include a phone number. Any browser pop-up showing 'your PC is infected, call Microsoft' is part of the scam. Force-close the browser and run a real Microsoft Defender scan.
Report to Microsoft at microsoft.com/reportascam, to the FTC at reportfraud.ftc.gov, and to the FBI IC3 at ic3.gov. Include the caller phone number, date, time, and any payment details.
Last reviewed: 2026-06-24 by the ScamRadar editorial team. We update this page when scammer tactics change or when official agencies issue new guidance.
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