Can you confirm which version of Copernicus you're running on which you see high CPU usage?
You can find the version number by doing: cat /etc/version
Also, are you using Real Time scanning mode? We have identified a bug in real time scanning mode which may cause this behavior. We have fixed the problem but it's not in the beta version. If you are using real time scanning mode, please switch to batch mode and see if the problem disappears.