A new report by specialist computer security company F-Secure shows that Android devices have become a major focus for malware writers. Google’s operating system has experienced a near 400 per cent growth in malware families since 2011. In the Mobile Threat Report, a freely downloadable PDF released on Monday, F-Secure statistics show 37 of the 49 new malicious software variants targeting smartphones were specially brewed for Android. The significant rise comes as malware for Symbian experiences a similar decline. This year there were observed to be over 3,000 different obfuscated APK files for delivering Android malware compared to only 139 a year ago.
The most common forms of malware on Android are Trojans. A growing trend is that Android Trojans deliver upon their promises! In his Quote of the Quarter, Sean Sullivan at F-Secure Labs explains: “One of the more interesting mobile phone malware trends we’ve seen in recent months is the growth of Trojans that “deliver on their promises”. In the past, most of the profit driven Trojans aimed at mobile phone users provided a decoy error message and attempted to convince the user that installation had failed...” Users investigating the failure often found they had been electronically taken advantage of. However the new Trojans deliver their illicit copy of promised software in full along with their payload. Sean Sullivan says this often means there is no immediate suspicion by the victim. “At this point, there is little to be suspicious of and nothing to troubleshoot. The user gets the game (or other app) that he was promised.” This means that the malware can have a more active and potentially profitable life.
In February Google launched a malware scanning system called Bouncer, to try and prevent infected apps being distributable within the official Android Play Store. Thus a lot of the infected apps available were found in the wild by F-Secure in third party app stores and/or in foreign markets. The most common profit aim of Android malware is to make money through sending texts to selected premium rate numbers, though there are also banking fraud apps and others. F-Secure's Sean Sullivan suggests keeping to the official Google Play Store for app downloads to minimize your Android malware attack risks.