Fraudsters bypass Google’s protections for the official Play Android store and published more than 20 fake modpacks for the popular game Minecraft. The apps are just empty shells designed to lure kids and teenagers that want to modify their gameplay. They do not deliver any malware but once installed, they make normal use of the phone almost impossible. Once installed, the bogus modpacks started to display full-screen advertisements aggressively. In at least one case, the sample would open a browser window with ads every two minutes.
Source: https://www.bleepingcomputer.com/news/security/fake-minecraft-mods-swamp-over-1m-android-devices-with-ads/