Well actually since android is used en mass' they are targeted much in the same way windows PC's are. However unless you download apps or packages from 3rd party sites on a regular basis you don't have much to worry about. Moreover, unless you do critical functions on your phone like online banking there is nothing critical to get infected, and if you are like me I do a full OS system-phone reinstallation about every 3-4 months anyway, making very sure I don't allow all my previous data to be restored other than contacts. On an android system you have to make sure you go through the checkboxes and uncheck the data you do not want restored.