Recently, a cyber security firm discovered that 238 apps on the Google Play Store had been infected with the "BeiTaAd" plugin. This plugin is the latest in a large and growing collection of advertising libraries that have been misused and abused by advertisers. It's a highly-intrusive adware plugin that displayed advertisements on smartphone lock screens and triggered video and audio advertisements even while the phone was asleep.
The BeiTaAd plugin was first introduced in 2018 as a simple package that allowed for the easy automation of online ads inside of perfectly legitimate apps. It's difficult for the lay user to detect BeiTaAd as it is never installed in the device, and it is not listed as an installed package. As a result, a user can't get rid of the plugin until the user uninstalls the entire application from the device.
One way the adware hides itself is by not firing up adverts once an infected app is installed. Instead, it waits at least 24 hours after the app is launched before cranking out ads. The cyber secuirty firm alerted Google to the adware problem, and it was subsequently yanked off the Play Store, though it looks like the damage had already been done given the 440 million installations.
Have you been bombarded with popup ads that seem to come out of nowhere? BeiTaAd is likely the cause. Check the apps on your phone and update to the latest versions first. If that doesn't do the trick, you'll need to go through your apps one-by-one to chase down the specific culprit.