The bug can be removed with most AV programs, the problem is that it will encrypt all the files in an algorithm that the AV cant deal with. The AV will only get rid of the host, not the trail it left behind. Like a tornado rolling through the plains. From the pop up, it should point you to the site for decryption, remember, it will also infect all mapped drives, and also the backups of those drives if not caught in time.