In short
Pop-ups saying your computer is infected, or calls from "Microsoft". How tech support scams work and what to do if someone accessed your device.
Top warning signs: A pop-up with a phone number; Unsolicited calls from big tech companies; Being asked to install remote access software.
First thing to do: Close the browser. If it won't close, restart the computer. Don't call the number.
How the scam works
When you call, a “technician” asks you to install a remote access app such as AnyDesk, TeamViewer or Quick Assist. They show you fake “errors”, then charge for a fix. Or, in the refund version, they claim to have refunded you too much and ask you to send the difference back from your online banking while they watch.
With remote access they can also install malware or move money themselves.
Red flags to look for
- A pop-up with a phone number. Real security warnings never ask you to call someone.
- Unsolicited calls from big tech companies. Microsoft and Apple don't cold-call about viruses.
- Being asked to install remote access software. Only do this with IT support you contacted yourself and trust.
- A “refund” that went wrong. The overpayment refund story is a script.
What to do if you get one
- Close the browser. If it won't close, restart the computer. Don't call the number.
- If someone calls you, hang up.
- For subscription emails, log in to the real account yourself to check.
If you already paid or shared details
Act quickly. It makes a difference.
- Disconnect the device from the internet and uninstall any remote access app they asked you to install.
- From a different device, change your email and banking passwords and turn on two-step verification.
- Call your bank. Then run a reputable security scan or get help from a trusted local repair shop.
More help: what to do after a scam, and where to report it in your country.
How to protect yourself next time
Keep security software with web protection on your devices
It blocks many known scam and malware websites and warns about dangerous apps. That matters most if you installed an app or "support" tool someone asked you to.
Free: Keep your phone and browser updated, and leave Google Play Protect or Microsoft Defender switched on. Both are free.
- Bitdefender Partner link Security suite for phone and computer with web and scam protection.
Use a password manager
It only fills in your password on the real website, so a look-alike login page gets nothing. It also makes a different password for every account, so one leak doesn't open the rest.
Free: Bitwarden has a free plan, and even the password manager built into your phone or browser beats reusing one password everywhere.
- NordPass Partner link Password manager with a free plan and a family plan for up to six people.
Compare the tools that help, and what each costs
Links marked Partner link may earn us a commission, at no cost to you. It never changes our advice, and the free option always comes first. Affiliate disclosure.
Questions people ask
Can a web page really infect my computer by showing a warning?
The scary pop-up itself is just a web page. Closing it is usually enough. The danger starts when you call and give access.
Have you had this one?
Tell other people what the message said and how it reached you. It helps someone recognise it before they tap.
No stories yet. Yours could be the one that warns someone.
Official sources and further reading
We check our guides against advice from government agencies and consumer protection bodies.
- How To Spot, Avoid, and Report Tech Support Scams (US Federal Trade Commission)
- Technical and Customer Support Fraud (US FBI Internet Crime Complaint Center)
- Service fraud, including tech support (Canadian Anti-Fraud Centre)
