Reuters:

Software pirates have hijacked technology designed by Apple Inc to distribute hacked versions of Spotify, Angry Birds, Pokemon Go, Minecraft and other popular apps on iPhones, Reuters has found.

Using so-called enterprise developer certificates, these pirate operations are providing modified versions of popular apps to consumers, enabling them to stream music without ads and to circumvent fees and rules in games, depriving Apple and legitimate app makers of revenue.

This is very bad news for Apple. They have long touted the safety and security of the App Store as a plus for consumers.