CoinVault is a file-encrypting ransomware program that targets Windows XP, Windows Vista, Windows 7, and Windows 8. This ransomware is part of the CryptoGraphic Locker family with the addition of offering one free file decryption to prove that they are able to do so. The ransom cost starts at 0.7 bitcoins and goes up after each 24 hours of the payment not being made. The infection is distributed via emails with ZIP attachments that contain executables that are disguised as PDF files.
Source: https://www.bleepingcomputer.com/virus-removal/coinvault-ransomware-information