Trend Micro has predicted that the number of malware threats targeting the Android mobile operating system will pass the one million mark by the end of 2013 From The Inquirer:

The increase will represent a near tripling of the number of threats presently known to target Android.

Trend Micro reported that at the end of 2012 it had detected roughly 350,000 malware samples that threaten Google's mobile operating system.

 Android malware threats will top one million this year