The Rokku Ransomware is a new infection currently being spread in email attachments. When infected a victim’s data files will be encrypted and then ransomed back for approximately $100 USD. At this time there is no way to decrypt the files for free, but this infection is still being analyzed for weaknesses. The first ransomware that I know of that uses the Salsa20 algorithm, which provides much greater encryption speeds compared to AES. The infection does not currently set any autostart locations for any files other than the ransom notes.
Source: https://www.bleepingcomputer.com/news/security/rokku-ransomware-encrypts-each-file-with-its-own-unique-key/