Lesson 3 of 12
Warning: Your Computer Is Infected
Sometimes a scary warning fills your entire screen while you’re browsing the web. This week, we’ll look at what that looks like — and you’ll learn exactly what to do.
This is a fake example — it can't affect your computer or accounts
CRITICAL SECURITY WARNING
Windows has detected a severe threat on your system. Error code: WIN-DL-0x80073B01. Your personal data, passwords, and banking information are at risk. DO NOT restart or shut down your computer. Contact Microsoft Certified Support immediately:
1-888-341-0753
Windows Defender Alert — Ref: MS-WD-20260311
Biggest red flag
The phone number
Real security software never shows a phone number. Microsoft, Apple, and Windows Defender do not ask you to call anyone from a popup. If you see a phone number in a warning, that’s all you need to know.
Supporting sign
“DO NOT restart”
This instruction keeps you trapped on the page. Closing the browser or restarting is actually the safe move — the scam only works if you stay.
Helpful, but not the main reason
The fake web address
The address bar shows “systemalert.net,” not microsoft.com. This can help, but the phone number alone is enough.
Decoration, not evidence
The made-up error code
Codes like “WIN-DL-0x80073B01” are invented to look technical. Don’t waste time looking them up.
What to do
Close the browser
Cmd+Q on Mac · Alt+F4 on Windows
If it won’t close, restart
Hold the power button for 5 seconds.
That’s it — the popup is gone
It was just a webpage. Your files were never in danger.
Let’s practice
This popup appears while you’re reading the news. You can’t find the close button, and it says not to restart. What’s the safest thing to do?
Example — not a real message
CRITICAL SECURITY WARNING
Windows has detected a severe threat on your system. Error code: WIN-DL-0x80073B01. Your personal data, passwords, and banking information are at risk. DO NOT restart or shut down your computer. Contact Microsoft Certified Support immediately:
1-888-341-0753
Windows Defender Alert — Ref: MS-WD-20260311
If a warning on your screen includes a phone number, it’s fake. Close the browser.
You’re getting better at this. Your next lesson arrives in about a week.
Help them keep up with a changing world
This is one of 12 lessons covering the scams targeting your parent right now. One arrives each week — no app, no account, just email.
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