First, note that your phone can't get infected thru' Virus..
If you are facing problem with your phone, back-up important data thru' Nokia Suite and dial *#7370# followed by 12345 (Default code unless changed by you) . See if the phone gets reset. This will erase all data from the phone memory. Now, connect your phone to PC and again thru' Nokia Suite check for any updates.. If available go for it, else re-install the Firmware ..
Restore your data and re-install the applications.. Now check ..