This PDF reader app has a million downloads on the Play Store – but it’s just adware
One of the most popular PDF reader apps on the Google Play Store is actually just a way to deliver potentially dangerous adware, experts have warned.
An investigation by Malwarebytes revealed that the imaginatively named “PDF Reader – Document Viewer” app did no such thing, but instead flooded users’ devices with annoying full-screen ads, even when they weren’t. are not used.
The company warns that the app has already been downloaded over a million and Google has yet to take it down, meaning more victims could soon be hooked.
In a blog post (opens in a new tab) Describing the scam, Malwarebytes notes how the app appears to trick users into not displaying ads immediately after installation.
Instead, it waits for a few hours, making it harder to track down which app caused the problem. When activated, however, the app fills the user’s home screen with full-page advertisements, preventing them from accessing their device unless they click on the advertisement.
Video advertisements are also displayed, effectively blocking the user from accessing their device, with the advertisements playing more and more frequently as the app goes unchecked.
Malwarebytes notes that the initial Google Play app listing page raised a few red flags that may have warned users that this was not a legitimate service. This includes a “Mature 17+” content rating – quite unusual for an Android PDF reader, and the developer name of “Fairy games” – again, not something you would typically associate with such a service.
“If you have many apps installed on your mobile device, this one can be very difficult to locate,” Malwarebytes noted. “Another reason not to blindly believe that you are safe when installing exclusively from Google Play. Even though the Play Store is by far the safest place to install apps on Android, it can also Fail from time to time. Having an anti-malware scanner, or anti-adware in this case, is a good idea. Stay safe!”