I wouldn't even think about unlocking it until you've cleared the malware. After that, go to the Facebook login page and get them to reset your password. If you do this before you clear the malware, it'll just get locked again.
If that is the case face book is giving some procedure how that can show your real identity so they can know that you are really the owner of that profile also you need to change the set up of your account once you're in so it won't happen again
