I have Sophos 9.6.1 active on my iMac 5K 2017. I'm looking at Activity Monitor right now and see that SophosScanD is using about 480 MB, while SophosWebIntelligence and SophosSXLD are both using about 40 MB each, plus there are a bunch of smaller Sophos services that are using around 40-50 MB total. So altogether about 0.6 GB. Luckily I have 24 GB RAM in this machine, but is this normal? 600 MB seems like way too much RAM for an anti-virus. And no, my Mac has never been infected, not even when I didn't use anti-virus, but I keep anti-virus running also to prevent infection of Windows files too. Any other free and good anti-virus programs that use less memory and CPU cycles?