http://globalthreatcenter.com/?p=2492
One question Juniper always get when discussing our research is if Apple’s iOS is more or less secure than Android? Maybe, but it’s not necessarily because of the security or lack of vulnerabilities in the platforms themselves. The main reason for the malware epidemic on Android is because of different approaches that Apple and Google take to police their application stores. Android’s open applications store model, which the lacks code signing and an application review process that Apple requires, makes it easy for attackers to distribute their malware. There is still no upfront review process in the official Android Market that offers even the hint of a challenge to malware writers that their investment in coding malware will be for naught. Until there comes a time that someone (ever heard of Charlie Miller?) figures out a tried and true way to get malicious applications into the App Store, Android will remain the target of mobile malware writers around the world.