Which antivirus product is this?

There's some general advice from MS about installing/configuring AV software to run on SQL Servers at https://support.microsoft.com/en-us/help/309422/how-to-choose-antivirus-software-to-run-on-computers-that-are-running

You might also want to check if you're running certain other pieces of software that hook into the SQL Server process space.  See https://support.microsoft.com/en-us/help/2033238/performance-and-consistency-issues-when-certain-modules-are-loaded-int - and the sp_Blitz check I wrote a while back - https://github.com/BrentOzarULTD/SQL-Server-First-Responder-Kit/issues/229 - and have a look at the contents of sys.dm_os_loaded_modules.