Google Play Store was found to host again more than 40 apps that pop up full-screen ads on Android phones. These ads are caused by malicious builds within these constructs posing as legitimate games or adblockers.
Avast security researchers discovered 47 such games and reported them to Google. About 17 of them are still available to download, unfortunately, such as Disc Go! on the Google Play Store. They all contain a trojan that displays ads even if you’re not using the app. It is part of the HiddenAds system, which Avast identified by analyzing the apps’ activity, features, and information.
How These Apps Work
Of the 47 apps, seven had the ability to launch the web browser on your device and display even more ads. One of the other spooky things these apps do is to hide their own icon so you can’t see it’s there; even if you manage to find it and remove it completely, the ads don’t always go away.
Because they are mostly games, it is likely kids, or younger phone users will download them without checking their scores on Google Play Store, nor read the reviews, which usually warn others about the incessant ads.
“Campaigns like HiddenAds may slip into the Play Store through obfuscating their true purpose or slowly introducing malicious features once already downloaded by users. It’s difficult to prevent adware campaigns since actors use one-off developer accounts for each app. While Google has been a great partner to remove malicious apps, users need to remain vigilant as they download new apps on their devices and check for telltale signs of a bad app such as negative reviews, extensive device permission requests and more,” said Jakub Vávra, threat analyst at Avast.
Usually, developers avoid detection by Google’s automatic verifying systems, which try to examine apps for malware and this type of adware, by creating a new developer account for every app. This is one sign of a malicious app.
This kind of thing has been going on for years now, with the most recent similar instance being 38 apps that were found to be malicious ten days ago. The 47 apps have been downloaded more than 15 million times. Here are the 20 most popular ones, so don’t install them; if you already have one or some of these builds, we recommend you delete them.
- Draw Color by Number – 1,000,000 downloads
- Skate Board – New – 1,000,000 downloads
- Find Hidden Differences – 1,000,000 downloads
- Shoot Master – 1,000,000 downloads
- Stacking Guys – 1,000,000 downloads
- Disc Go! – 1,000,000 downloads
- Spot Hidden Differences – 500,000 downloads
- Dancing Run – Color Ball Run – 500,000 downloads
- Find 5 Differences – 500,000 downloads
- Joy Woodworker – 500,000 downloads
- Throw Master – 500,000 downloads
- Throw into Space – 500,000 downloads
- Divide it – Cut & Slice Game – 500,000 downloads
- Tony Shoot – NEW – 500,000 downloads
- Assassin Legend – 500,000 downloads
- Flip King – 500,000 downloads
- Save Your Boy – 500,000 downloads
- Assassin Hunter 2020 – 500,000 downloads
- Stealing Run – 500,000 downloads
- Fly Skater 2020 – 500,000 downloads
How to Avoid Installing Adware Apps
To make sure you never install apps that display unwanted ads, read the reviews, and look at the app’s rating in Google Play Store. Look at which permissions the app requests and deny unnecessary ones, such as permissions to access your contact list, your gallery, and so on. Finally, install and use antivirus software for Android to protect your device.