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This dirty trick could force you to click nasty popups

Another week, another shoddy ad format trying to make the internet a little worse for everyone. It’s such a big deal, there’s even a shorthand for such malicious ads, malvertising.

This week in malvertising, popup ads that increase in size rapidly so that users will click on the advert instead of the close ad button. The popup will look pretty standard, including the expected close button in the top right. However, CSS code from the page will expand the ad as the user moves their mouse to click it, meaning most users will miss and click the advert instead.

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The CSS code hidden in the ad keeps track of the mouse cursor and reacts immediately as soon as it comes over the little ‘close-this-ad-and-never-bother-me-again’ X, moving the ad at the exact millisecond to ensure the ad is clicked on, maximising their ad revenue.  
This is a bit naughty, and it’s irritating for users that are bamboozled by the case of the rapidly expanding popup ad, too.

This has been picked up by the security boffins are Malwarebytes, who spend most of their time looking at the dirty tricks of malvertising outfits and warning innocent net users off of their more heinous schemes.

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Worse, Malwarebytes warns that these dodgy ads could direct you to sites performing ad fraud or even sites hosting credit card-stealing code and other general maliciousness. 

The fix for this is a little complicated, too. A standard ad blocker can’t correct the problem with the CSS code, and it’s unclear exactly how browser outfits are going to fix things up either, although there’s no doubt they’re trying to work out a solution while you’re reading this.

Been caught out by expanding popups, or other nasty ads? Let us know on Twitter at @TrustedReviews

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