Revealed: How to beat the 'Windows Defender' scam

Scammers are using fake Windows Defender pop-up messages to convince PC users to hand over hundreds of pounds.

In reality, however, these warnings are completely false and have nothing to do with Microsoft. They are caused by trojan malware that can delete, block, modify, leak or copy data. But your device isn't affected by this trojan – it's simply a window trying to convince you to call the number on-screen.

Below, we explain how to remove these pop-ups for good. Plus, we've got details on how we uncover the best free and paid-for antivirus software.

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Question of the month: how do I get rid of the 'Windows Defender' scam?

'I've had a Windows Defender pop-up message appear on my laptop that I can't get rid of – it's taken over my screen and is telling me my device is under threat from a detected Trojan program and I need to contact Microsoft. What should I do?'

Which? Tech Support member

Our expert says:

'This is a well-known scam that we regularly get contacted about – it has nothing to do with Microsoft, is extremely annoying and very convincing.

The message can take over your entire screen, so you can see why some people feel obliged to call the on-screen number. The call usually revolves around the scammer convincing you that your machine is 'infected' and a payment (typically a few hundred pounds) by bank transfer or gift cards will resolve the issue. The scammers are usually very persistent.

Don't call the number, though, as there's an easy fix. Just follow the steps below.'

Which? Tech Support

How to protect your PC

1. Press Ctrl + Alt + Del on your keyboard and select Task Manager. From here, you can close your web browser (whichever one you use to access websites; Chrome or Firefox, for example). To close it, right-click your browser and select End task.
2. Next, you need to disable your browser notifications in both your computer's settings and the browser itself. (shown below) Click the Start Menu or press the Windows key on your keyboard > Settings > (on Windows 11, also select System) Notifications & Actions and toggle your browser to Off.
3. Open your browser again and go to its settings – from here, you need to look for privacy and security, and then notifications (this will differ, depending on your browser – use a search engine to help you if you can't find it). For example, in Chrome, you select the top right icon showing three dots > Settings > Privacy and security > Site settings.
4. Scroll down, select Pop-ups and redirects, then select Don't allow sites to send pop-ups or use redirects.

There are no residual effects once the page is closed and notifications are turned off – your computer will not be infected in any way.

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Which? Best Buy antivirus software

If you're looking for an effective program to safeguard your personal data, the results of our in-depth lab tests can help.

To uncover the top free and paid-for antivirus software, we run through a series of checks. Our experts bombard software with tens of thousands of threats, including viruses, ransomware and phishing attacks. This process is repeated multiple times a year, as calls to Which? Tech Support confirm that new threats are emerging all the time.

To calculate an overall score for antivirus software, we also study how easy it is to use and how many pop-ups you'll have to deal with while you use it.

For more details, see best antivirus 2024. Which? Tech subscribers, you can take a look back at the April issue of Which? Tech magazine.

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