has anyone used scan guard

ScanGuard is a scam app, not a legitimate anti-virus program. Do not use it.

The ransomware recently in the news only effects PC so there is no need to do anything on your Mac for that.

I would recommend against the installation of any AV software on the Mac including ScanGuard. There is nothing for them to do on the Mac but cause problems. The best defense is to keep macOS upgrade on your Mac. It will provide you with protection.

The vast majority of posts here have shown all offerings of 3rd party Anti-Virus on the mac:

Causes huge problems with OS X and seriously interferes with macs ability to keep itself clean when it's not crashing the system or causing Kernel Panics.

Is coded by idiots who are guessing their way around what securities Apple put in because unlike Microsoft Apple does not share this info with anyone.

Is marketed by liars who think since they have a good rep in the windows world they should be able to sucker mac owners and take their money by telling them a lot of very untrue information.

Has repeatedly been shown to be unable to remove basic adware and malware

Has never faced an actual Mac Virus because there aren't any a this time and their reaction to it is complete speculation.

If you want to run anti-virus buy a Windows PC, if you want to screw up your Mac and make it pretty much inoperable and not protect it in any way run an anti-virus.

Rudegar wrote:

if you get them from osx app store then you at least know they will not cause trouble

Actually, if you get anti-virus software from the Mac App Store, that's when you're highly likely to get scammed. Most of them there won't actually detect much, if anything at all.

think they are all pretty much scams

if you get them from osx app store then you at least know they will not cause trouble or be ransomware apps themselves