What this is about
Five situations on your computer or phone. Something pops up — and you decide what to do. There can be more than one good answer.
What you practise
Close an alarm window calmly — without calling anyone, allowing remote access or typing in anything a page asks for.
Tip: choose your answer from the list. Don't press the keys it mentions here in the exercise — they would close this page.
The interactive exercise needs JavaScript. Without it, you can read through all messages with their explanations here.
Security warning: your computer has been locked
Dangerous malware has been found on your computer (error code 0x80070422).
Your passwords, photos and bank details are at risk.
Do NOT switch off your computer. Call technical support immediately:
- ✗ Call the number — someone there will help. – That's exactly what the scammers want. On the phone they'll talk you into allowing remote access or paying for a supposed repair.
- ✗ Click “OK” or “Start scan” in the window. – Buttons in this window belong to the scammers. A click often starts a download or opens even more windows.
- ✓ Close the window or browser tab (the tab at the top of the browser) — Ctrl + W, on a Mac ⌘ + W. – Right. It's just a web page dressed up as a warning. Closing it is enough. If the keyboard doesn't respond, hold down the Esc key for two seconds — the browser then leaves full screen. If that doesn't work either, quit the browser: on Windows, if necessary, via the Task Manager (Ctrl + Shift + Esc); on a Mac with ⌘ + Option + Esc. If the browser then offers to restore your last pages: say no — otherwise the warning is back.
- ✓ Restart the computer. – Also fine: a restart ends the web page. The threat “do NOT switch off” is part of the trick. Afterwards: if the browser offers to restore your last pages, say no — otherwise it opens the warning again straight away.
A trap. Real security software doesn't show you a phone number to call. The window is a web page in full screen — and it can be closed.
Your device is slow! 17 problems found
Storage 94% full
Battery damaged — act now
Install the cleaning app now and rescue your device.
- ✗ Tap “Clean now” and install the app. – Apps like this often secretly cost money through a subscription, show ads or spy on you. A web page can at most see your battery's charge level — it can't detect any damage.
- ✗ Try “Start scan” first — it can't hurt. – The “scan” is just an animation. It's meant to impress you so that you install afterwards.
- ✓ Close the page and carry on. – Right. It's advertising dressed up as a warning. Real information about storage or battery is shown by your device in its own settings.
A trap. Web pages can't detect battery damage or full storage — “warnings” like this are advertising with scare tactics.
Confirm that you are human
Press the Windows key and R at the same time.
Press Ctrl + V to paste the verification code.
Press Enter.
- ✗ Follow the three steps — it's only a check. – That's the trap: the page has secretly put a command on your clipboard. With Windows + R, paste and Enter you run it yourself — and bring malware onto your computer.
- ✓ Close the page and don't type anything. – Right. No genuine check asks you to press key combinations or paste something into a window on your computer. Pages that want that are a scam.
- ✓ Ask someone who knows about computers before doing anything. – Also good: ask first, act later. The answer will be: close the page, type nothing.
A trap (experts call it “ClickFix”). No web page needs you to paste commands into Windows + R, a terminal or PowerShell — however real the check looks.
Critical browser update required
This page can't be displayed because your browser is no longer secure.
Download the latest version now to continue.
- ✗ Click “Update now” and open the file. – The downloaded file isn't an update, it's malware. Real browser updates don't come through a web page.
- ✗ Keep reloading the page until it works again. – Reloading changes nothing — the prompt is part of the page itself. Close it.
- ✓ Close the page and, if needed, check for an update in the browser's settings. – Right. The browser brings its own updates — automatically or through its settings, not through a web page you happen to visit.
A trap. Updates for your browser come through its settings or automatically, not through a web page. The message is bait for a file containing malware.
Updates available
Security updates are ready for your device.
You can install them now or choose a later time.
- ✓ Install now. – Good. Updates through your system settings close security holes. Save any important work first.
- ✓ Remind me later and install tonight. – Also fine — just don't put it off forever. Security updates matter.
- ✗ This is surely a scam too — always dismiss it. – This message comes from the system itself, not from a browser window: no phone number, no panic, no deadline, no download from a web page. Ignoring real updates for good makes your device less safe.
Genuine. The message comes from your system settings, shows no phone number and applies no pressure. Not everything that pops up is a trap.
Four things to remember
No phone numbers
Real security warnings never ask you to call a number. A warning with a phone number is a scam.
Closing is allowed
A scary window in the browser is just a web page. Close it — if necessary, quit the browser or restart the computer. Afterwards, don't let the browser restore your last pages.
Type nothing a page asks for
No genuine check asks you to press key combinations or paste commands. Updates come through your browser's or device's settings, not through a web page.
No remote access
Never let a stranger connect to your computer, however friendly they sound on the phone.
Protection is built in
Windows comes with its own antivirus, Windows Security, and so does the Mac. You don't need security software that a web page pushes on you.
All companies, people, addresses and numbers in the exercises are invented. Any resemblance to real companies or people would be purely coincidental and unintended.