It’s always a good idea to have a good anti virus program. Kapersky is a good one as well as Malwarebytes, Norton and Webroot. There are some free versions but they may lack some important features like real time protection, and other types of issues like keyloggers, rootkeys they scan for. A paid for antivirus, like Kapersky and others offer a bit more security. I think it’s worth the cost when you read about all the problems affecting systems today. The paid programs may have more current database used for protection where the free ones update the virus definition databases less frequently.