Does your information below also apply to "Symantec Endpoint Protection 11.0.5002.333"?
Client SW was pushed down from the control center on the server...
The high CPU usage in Rtvscan.exe is caused when the following registry path to NavLogon.dll is not added during the installation of Symantec AntiVirus:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon\Notify\NavLogon\DllName
Add the following Key and values to
Start regedit.exe and browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon\Notify
Right-click on the Notify key, and select New > Key.
Type NavLogon for the key.
Right-click on the NavLogon key, and select New > String value.
Type DllName for the String value.
Right-click on the DllName String value, and select Modify.
For the Value data, type C:\WINDOWS\system32\NavLogon.dll (default OS install path)
Click OK and exit the Registry Editor.
After making registry changes, restart the computer