With any type of crypto* virus, if the machine is infected, the only way to recover is by restoring from a known good backup or re-imaging the machine. Most of this crypto is unbreakable.
Symantec does not have a specific removal tool. Norton Power Eraser may help to eradicate it but it won't unlock the encrypted files:
https://www.symantec.com/security_response/writeup.jsp?docid=2013-091122-3112-99&tabid=3