https://motherboard.vice.com/en_us/article/kzkxje/apple-ban-cryptocurrency-mining-in-app-store

Hackers are getting creative when it comes to getting websites and apps to hijack unsuspecting users’ computers to generate digital tokens for profit. After a Mac app called “Calendar 2” (AKA Calendar 2: The Scheduling) started mining the cryptocurrency Monero in the background on user’s devices, for example, Apple pulled the app from the App Store and it later re-launched without a mining feature.

Now, Apple has updated its guidelines for app developers to specifically ban on-device cryptocurrency mining in apps. Under the section relating to excessive resource consumption, Apple’s policies now include language that bans “unrelated background processes, such as cryptocurrency mining.” Under the section relating to cryptocurrencies generally, Apple’s policies now say that “apps may not mine for cryptocurrencies unless the processing is performed off device (e.g. cloud-based mining).”