Solved! Is antivirus protection needed for Linux Ubuntu 18.04?

Solution
With Linux, keeping up to date with patches and updates is much more important than anti-virus. Because Linux is used mostly on servers with no actual user, most of the security concerns in Linux are from a software vulnerability allowing an intruder to access your system, rather than a virus accidentally run by a desktop user. The updates will fix vulnerabilities as they are discovered. (Granted for home use, your router's firewall should block most intrusions. Be sure to update your router's firmware regularly - most routers are just tiny computers running Linux.)

Ubuntu should be configured by default to auto-update. But you should verify that it is working (sometimes the correct repository addresses do not get entered properly...
With Linux, keeping up to date with patches and updates is much more important than anti-virus. Because Linux is used mostly on servers with no actual user, most of the security concerns in Linux are from a software vulnerability allowing an intruder to access your system, rather than a virus accidentally run by a desktop user. The updates will fix vulnerabilities as they are discovered. (Granted for home use, your router's firewall should block most intrusions. Be sure to update your router's firmware regularly - most routers are just tiny computers running Linux.)

Ubuntu should be configured by default to auto-update. But you should verify that it is working (sometimes the correct repository addresses do not get entered properly by the install script).
 
Solution