Recently, I tested several antiviruses in VirtualMachine, and here are my 2cents: S Tier Kaspersky Free: Shows good scan detection rate, powerful behavior detection, runs fast with fluid performance, and has the least false positives. A Tier Bitdefender Free: Performs decently in scan detection rate and great behavior detection; however, it’s a bit laggy on my VM and has high false positives. Avast/AVG Free: Has a nice, organized interface with a great detection rate, decent behavior detection, and has few false positives. The downside is the annoying pop-up and being a bit sluggish. Windows Defender: Has no UI and a buggy Windows Security Center interface, but it boasts a high detection rate. However, its behavior detection is weak and has a high false positive rate. SEP: Technically not free, but I will give my opinion anyway. It has a dead-slow scanner, decent detection rate, good behavior detection, and decent false positive rate, but on an old Windows 98 UI. EES: Like SEP, it’s not technically free, but it shows a high scan detection rate with non-existent behavior detection; however, it’s light and has a great interface, with low false positives when PUA is turned off. B Tier Avira Free: incredibly laggy and buggy performance with a decent detection rate, non-existent behavior detection, and a decent false positive rate. F-Secure Protection (beta is free): Sluggish when opening exe, decent detection rate, decent behavior detection, high false positives. Trellix: Technically not free, heavy resource usage, laggy and sluggish performance, decent detection rate, high false positives. Drweb beta***(beta is free)***: This shows a slow scan, slow performance, low detection rate with decent behavior detection, and a low false positive rate. 360 Toal Security Suit: The cloud database in this version is much smaller than one in China , resulting in a decent detection rate. It has behavior detection and has few false positives. However, overall it’s just a nerfed version of the original. C Tier Ahnlab Lite: Decent Detection rate, No behavior detection. Malwarebytes Free: Buggy, slow performance, decent detection with no behavior detection and real-time protection for free version. To be honest, any mainstream antivirus + common sense will keep you safe. It’s no longer the XP generation. Answer from COVID-19VIRUS on reddit.com