Fix for HOWDECRYPT attack

This morning we encountered the HOWDECRYPT ransomware. It has affected, as best we can tell, one of our workstations and then all of the mapped connections on this workstation. Unfortunately, the mapped connections include all of our backup drives. Is there a way to recoved the encrypted files? My understanding from Symantec help is I can use Power Eraser to eradicate the ransomware, but no one has been able to tell me if - or how - I might recover the files we had on the workstation or assorted attached NAS devices. Also based on those discussions we plan to install Endpoint SBE 2013, which we hope works better than what protection software is installed now, Would appreciate any direction . . .