A newly discovered adware app on the Google Play Store with over a million downloads sneakily hides an aggressive form of adware, and the developer has made it difficult to detect the source of the annoying full-screen ads the app comes with.
Tracked by Malwarebytes (opens in a new tab)The PDF reader app uses common adware development kits (SDKs) and its own SDK to display full-screen ads that appear on a phone, even when the app is not being used.
As the report points out, the SDKs used, such as Applovin and Facebook Ads, are fine for displaying ads within the app, allowing it to be free. However, bombarding users with frequent advertisements, even video ads, outside of the app makes it a malicious form of adware.
Also, full-screen ads take a few hours to start displaying to make it more difficult for the user to figure out where the displayed ads are coming from. Malware researcher Nathan Collier recorded every step of how the adware runs, noting that the PDF reader app will “sound like a charm” when the screen is locked, and launch a full-screen ad once unlocked.
Even after the first ad is shown, another ad appears in the form of a video soon after. Collier says that after the initial announcements, they start showing up more often. The app is said to be around since November 2021, and with over a million downloads according to its Google Play listing, many users might download the app without knowing it.
Don’t let adware ruin your phone
It’s always a good idea to be careful about the apps you download, and many malicious apps that hide adware or even malware will have clear signs that they’re suspicious.
As an example. the PDF reader has some suspicious flags. First of all, it is classified as “For ages 17+”. There is no reason for a PDF reader to have any kind of age restriction, especially one that is for “mature” audiences. Second, the app is developed by “Fairy games”, which doesn’t exactly match the type of app being offered.
Adware is a sneaky way for threat actors to generate revenue by automatically displaying an unsightly number of online advertisements, usually without the user’s knowledge or consent. Unfortunately, it can also lead to malware, which means it’s worth getting rid of.
The PDF reader app, known as “PDF reader – document viewer”, is currently on the Google Play Store (here), so make sure you stay away from it and look for more reliable PDF readers. If you recognize this app on your device, make sure to remove it in order to get rid of annoying pop-up ads.
The best way to get rid of adware (and any malware it may bring with it) is by downloading one of the best antivirus applications. These cybersecurity programs can scan your device and remove adware, as well as prevent future adware downloads and malicious pop-up ads.