Is virus protection needed for iMacs?

Yes. It appeared like the processes were using inordinate amounts of CPU all the time once they started. The user never reinstalled it again after that.

Allan

Allan Eckert wrote:

Yes. It appeared like the processes were using inordinate amounts of CPU all the time once they started.

But was it a full disk scan or just the on access scanner that was running?

The user never reinstalled it again after that.

Which doesn't rule out the possibility that the original installation was damaged, right? Think about how often wonky behavior is fixed by say running a combo update because it replaces some file that has been corrupted. In those cases you would not automatically assume the OS was at fault, would you?

Neither I nor the owner of the Mac figured it was worth the effort so we didn't even try.

TTBOMK it was not doing a full scan.

Allan

How are you so sure that there aren't any viruses?