Symantec Endpoint Protection client uses high CPU after downloading Intrusion Prevention policy with large number of exceptions.
High CPU usage by ccsvchst, smc and/or smcgui processes for a few minutes; symptoms should recur only when there are subsquent policy changes that trigger a re-download of Intrusion Prevention policy by the client.
This issue is resolved in Symantec Endpoint Protection 12.1 Release Update 2 (RU2). For information on how to obtain the latest build of Symantec Endpoint Protection, read How to obtain an update or an upgrade for your Symantec corporate product.
Symptoms only occur in SEP 12.1, and not in SEP 11.x