Fotis is inspecting a system where the user reported a strange error message and the inability to access files. He sees the window shown here. What type of malware should Fotis suspect?

Messages similar to the one shown here are indicative of a ransomware attack. The attacker encrypts files on a user's hard drive and then demands a ransom, normally paid in Bitcoin, for the decryption key required to restore access to the original content. Encrypted viruses, on the other hand, use encryption to hide themselves from antivirus mechanisms and do not alter other contents on the system.