Dozens of Android apps designed to flood phone screens with ads hide their malicious behavior when a Google IP is detected. Collectively, they were installed 8 million times. The developer of the 42 apps kept this behavior hidden until it passed all verification from Google. The apps included the functionality advertised in their description and adware acted as a secondary effect. Some of the adware apps in Google Play were in Apple’s App Store but did not include the annoying behavior in the way they were distributed across 24 countries.
Source: https://www.bleepingcomputer.com/news/security/malicious-android-apps-hide-ads-from-google-employees/