Written & reviewed by the GotAScam security team · Updated August 2026
The short answer

Yes. Microsoft, Apple, and antivirus companies do not put a phone number in a pop-up warning, and they never cold-call you about a virus. These scams exist to get you on the phone so a fake technician can take remote control of your computer and your money.

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What this scam looks like

There are two versions. The pop-up version hijacks your browser with a scary full-screen page — sirens, “your computer has been locked,” a Microsoft logo, and a support number. The cold-call version is someone claiming to be from Microsoft or your ISP saying they’ve “detected a problem.”

Either way, if you call or let them in, they’ll install remote-access software, show you harmless system messages as “proof” of infection, and charge you hundreds to “fix” it — or quietly log into your bank while connected.

Example — Full-screen browser pop-up
** WINDOWS DEFENDER ALERT: ZEUS VIRUS DETECTED ** Your computer has been blocked for security reasons. Do NOT restart. Call Microsoft Support immediately: +1 (855) 555-0173 to prevent data loss.

Example is illustrative and de-fanged; links are shown broken so they can't be clicked.

Red flags to watch for

What to do if you got one

  1. For a pop-up: don’t call the number. Close the tab, or force-quit the browser (Ctrl+W, or restart it). The “virus” is just a web page.
  2. For a call: hang up. Don’t let anyone remote into your computer because they called you.
  3. If you already gave access, disconnect from the internet, uninstall any remote-access app they added, run a real malware scan, and change important passwords from a different device.
  4. Called your bank or paid? Contact your bank/card issuer right away to dispute and re-secure accounts.
  5. Report it at reportfraud.ftc.gov. Unsure if a warning is real? Paste it into GotAScam.

Frequently asked questions

Is my computer actually infected if I see this pop-up?

Almost never. The pop-up is a web page designed to look like a system alert. Closing the browser removes it. A real infection doesn’t give you a toll-free number to call.

They said they were from Microsoft and knew my name. Legit?

No. Microsoft does not make unsolicited calls about your PC. Your name and number are easy to obtain; it’s a script, not proof.

I let them remote in for a few minutes — am I compromised?

Assume they may have installed software or seen saved passwords. Disconnect, remove remote-access tools, scan for malware, and change passwords (especially banking and email) from a clean device.

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