Many security researcher and the German security agancy BSI identyfied a new ransomware named „Locky“. It encrypts your data using AES encryption and then demands .5 bitcoins to decrypt your files.

Source:
BleepingComputer

Locky installed via a E-Mail attachment:

Locky is currently being distributed via email that contains Word document attachments with malicious macros. The email message will contain a subject similar to ATTN: Invoice J-98223146 and a message such as „Please see the attached invoice (Microsoft Word Document) and remit payment according to the terms listed at the bottom of the invoice“.  An example of one of these emails can be seen below.

Further details:
SecurityAffairs