https://techcrunch.com/2019/04/01/android-security-0-04-of-downloads-on-google-play-in-2018-were-potentially-harmful-apps/

Google’s Android, now 10 years old, has not been a stranger to security issues over the years. But with the mobile operating system now installed on over 2 billion devices globally, Google has been taking an increasingly firmer grip on trying to bring the problem under control. Now, the company has published its lengthy annual update to take stock on just how well that is going.

It’s a slippery slope to be sure, with the number of apps and the enterprising attempts to maliciously exploit them both growing. To wit, 0.04 percent of all downloads from Google Play were classified as potentially harmful applications (PHAs) by Google, versus 0.02 percent in 2017 — an increase in part because Google is growing the categories it’s identified and is tracking.