Every month or so there is a new story that comes out about how much malware can be found on Android or in the Google Play Store. Unfortunately, most of the reports don't include all of the information that you'd expect. Stories about malware on devices often don't mention what harm is actually caused, nor that most malware comes from sideloading, or devices without the Google Play Store...
Source: http://www.phonearena.com/news/Google-says-less-than-.001-of-Android-malware-evades-Google-Play-security-to-cause-harm_id47960
Source: http://www.phonearena.com/news/Google-says-less-than-.001-of-Android-malware-evades-Google-Play-security-to-cause-harm_id47960