F-Secure's latest Mobile Threat ReportPDF for the last three months of 2012 names Android as the home of 96% of the new "mobile threat families". Of 100 new threat families detected in that quarter, 96 of them were based on Android, up from the previous quarter's 49 out of 74, and only 4 were resident on Symbian, down from 21 in the previous quarter. The numbers are for newly detected families of malware only and do not reflect overall numbers found in the wild.

According to the F-Secure numbers there were no new malware families found for iOS, J2ME, BlackBerry or Windows Mobile at the end of last year. F-Secure says that over all of 2012, 79% of the malware families found were for Android, 19% for Symbian and less than 1% each for the four other platforms. The findings seem to confirm that the makers of malware have set their sights firmly upon Android.

F-Secure does include various hacking and monitoring tools, spyware and even anti-theft software for tracking stolen phones on their lists of possible threats, on the basis that some of it may have been installed without the owner's knowledge. Of the threats in the last quarter though, 53% were trojans, 27% were termed "riskware", and 10% were monitoring tools. The company also saw a swing towards profit-motivated mobile malware with 173 or the 301 threats in the year being profit motivated, compared to 2011 where it was a near half and half split between that and not being profit motivated. 141 of the 173 profit-motivated threats were on Android.

Interestingly, F-Secure didn't break down the malware by source so it's not possible to see if there are any common vectors or if any one channel of infection is becoming more or less used. Google, for example, has been enhancing its malware defenses in the Play store, but it is not possible from this report at least, to determine whether this has had an effect.