I’m using Avast Free Antivirus (version 17.7.2314) as a secondary antivirus (supposedly in passive mode) along with Malwarebytes Free, Reason Core Security Free, and weekly scanning with Herd Protect (free “online scanner” using “68 antivirus databases”). Reason Core and Herd Protect are by the same company. I’ve been using Bit Defender Internet Security 2018 (upgraded from 2017) as primary protection suite.
[b]Why Using Multiple Antivirus Programs is a Bad Idea[/b] https://www.kaspersky.com/blog/multiple-antivirus-programs-bad-idea/2670/