The last couple of years have seen a rise in the volume of malware targeted specifically at various mobile operating systems, including Android, iOS and Symbian. Researchers have found that many mobile malware samples also show up on the desktop for various reasons, giving them a view into the prevalence of malware on key platforms. Malware authors use to infect mobile devices is to place the malicious code inside a legitimate app and then submit it to an app store. This has been the favored tactic for attackers targeting the Android platform, as the official Android Market has a fairly permissive app acceptance policy.
Source: https://threatpost.com/mobile-malware-showing-desktop-pcs-102011/75777/