The spread of hidden code that hijacks computing power to mine for cryptocurrencies is spreading even further, as security researchers have discovered hidden cryptomining code in Android apps listed on the Google Play store.

Researchers at Trend Micro Inc. made the discovery, detailing in a blog post Monday that they had found apps “with malicious cryptocurrency mining capabilities on Google Play” that used dynamic JavaScript loading and native code injection to avoid detection. The apps, no surprise, were using the same code developed by Coin Hive that has been found hidden on potentially thousands of websites and more recently was claimed to have affected 500 million users.

In a similar route to that taken by those spreading malware in Android apps, the apps found to be running hidden cryptomining scripts were disguised as legitimate apps. They included a wallpaper collection, a wireless safety app and, strangely, an app called “Recitiamo Santo Rosario Free” that apparently helps Catholics make prayers of the Holy Rosary.

“These threats highlight how even mobile devices can be used for cryptocurrency mining activities, even if, in practice, the effort results in an insignificant amount of profit,” the researchers noted. “Users should take note of any performance degradation on their devices after installing an app.”

Although the identified apps have since been removed from Google Play, the mere fact that they had managed to be successfully listed there without triggering any alerts is a concern in itself. It’s not entirely clear how they managed to slip past Google’s checking features.

But there is some suggestion that the cryptomining code may have been added to the apps after they were already listed. In turn, that begs another question as to why Google isn’t regularly scanning existing apps in Google Play for malicious code in addition to scanning them when they are listed.

In related news, or karma, Coin Hive itself was reported to have been hacked last week. According to The Hacker News, hackers hijacked the code served by Coin Hive to make those running it mine cryptocurrency for the hackers’ benefit, proving that there is indeed no honor among thieves.

Image: Trend Micro