Hello,
If you disable tamper protection you can control the SepMasterService service.
Type the following without quotes.
“sc queryex SepMasterService” and press enter.
Try the command from command prompt -
taskkill /pid ccSvcHst.exe /f
Check these articles:
How to detect Symantec Endpoint Protection services in version 12.1
http://www.symantec.com/docs/TECH162901
Removal of SEP 12.1 client fails with error code 1603.
http://www.symantec.com/docs/TECH180344
Hope that helps!!!