Ryun Ransomware is a sophisticated piece of code written on the lines of Hermes Ransomware. It demands 15 to 35 BTC from it victims to recover files.
Update: A new Sample of Ryuk Ransomware is spreading in the wild that implements Wake on LAN (WOL) feature. It extracts IP address form its victims ARP table and send a WOL request on the network. If it able to awake a host it mounts "C$/admin" share, if successful the Ryuk deletes volume shadow copies and encrypt the drive. It appends "HARMES" to the end of the file as marker to itself that file is encrypted.