Malware Attacks Deletes information from hard drives

Users are encouraged to back up important personal files such as photos or important documents. But users are finding that those documents appear to have been removed from the hard drives, and apparently deleted forever. Customers are finding information mysteriously deleted from their hard drives amid an apparent malware attack. While some users say their devices have been entirely reset to how they were when they were bought, or show a request for a password that they have not set, most people say the files have simply disappeared. What is the way forward in fighting malware attacks ?