For example, Android malware has increased 472% since July alone. So in a word, 'Yes', you do need smartphone antivirus software…for Androids. What's interesting about this statistic is that 55% of the identified malware threats come from user installed apps that work in the background to retrieve personal information stored on the phone - which is particularly worrying if you use your smartphone to do mobile banking or store important information on it. A further 44% of the found malware was determined as SMS trojans horses, that automatically sent text messages back to premium rate numbers. A resounding case for antivirus software really.
iPhones however have a lot better track record in terms of security and malware. So much better in fact that according to 'McAfee Threats Report: Second Quarter 2011' there have been no threats to iPhones that haven't been Jailbraked. The reason for this is almost certainly because of the meticulous 'walled garden' approach that Apple take towards the apps they allow on the app store. So whereas it is strongly advised that you do have antivirus software for an Android, at present you're relatively safe with an iPhone so long as Apple don't let their policing standards slip.
Windows Phones are also venerable to unscrupulous apps. So much so that the director of product management for Windows Phone Market place, Todd Bridge, was openly talking about his company's plans to deal with future malware outbreaks in a PC Pro interview. Biggs said that Windows planned to simply remove potentially dangerous apps from its online catalogue, "But if it was very rogue [app] then we could remove applications from handsets - we don't want things to go that far, but we could,"
The key thing to bear in mind with all mobile phone malware is that it is still a relatively young beast, and because of this, the future is unknown (sorry for the horrible cliché). Therefore antivirus software is of course a good idea, and it's also worth remembering that there is a collective benefit to installing antivirus software on your device as the antivirus companies can then track and record smartphone malware activities on a large scale. However if you do instal a free antivirus application on to your smartphone, don't be fooled by thinking you're safe. See Free Android antivirus 'doesn't work' to find out why.
Finally, if you are serious about your smartphone security then you need to be able to protect yourself from the threat of physical theft and instal software that allows you to remotely track, lock and wipe your device.
