Hello! I'm using Malwarebytes, but hear there is free scanner from BitDefender in App Shop https://itunes.apple.com/us/app/bitdefender-virus-scanner/id500154009?mt=12 Any opinions? Would it be safer to have two scanners to use from time to time? Is BitDefender safe or could it do something bad with my Mac? It's even in App Store so, respectable enough?