There is a ransom malware that is running wild in Ukraine called XData. It is also infecting users in Estonia, Russia, and Germany. Bleeping Computer says it is greatly infecting users in Ukraine. I don't know if Clam AV will get a signature for it, so below are 2 of my signatures. If you need the signatures, highlight and copy them in a Notepad or other word processing file as text for the filetype, and name the file Sigfile.mdb. Copy the file to the C:\ProgramData\.clamwin\db folder. I hope this will hlep some users.

7680:e3646fdc1a55d6eb55407e800462968c:Win.Trojan.Ransom.XData-051917.1911
809472:aabdb37347b53f0aaac651219e3b6443:Win.Trojan.Ransom.XData-051917.1908

Regards,