Symantec refers to Jaff as Ransom.Enciphered
AV detection:
https://www.symantec.com/security_response/writeup.jsp?docid=2014-050702-0428-99
IPS detection:
https://www.symantec.com/security_response/attacksignatures/detail.jsp?asid=28713
https://www.symantec.com/security_response/attacksignatures/detail.jsp?asid=28019
Technical details:
https://www.symantec.com/security_response/writeup.jsp?docid=2014-050702-0428-99&tabid=2
Symantec has multiple detections for all the ransomware over the past couple weeks. Some are generically named. As long as you're up to date you are protected.
This article provides additional guidance:
https://www.symantec.com/connect/articles/hardening-your-environment-against-ransomware