How to install and use ClamAV on Ubuntu 20.04

ClamAV is an open-source and free antivirus software toolkit able to detect many types of malicious software, including viruses, trojans, malware, adware, rootkits and other malicious threats. In the following tutorial, you will learn how to configure ClamAV on Ubuntu 20.04 LTS. The same principle will work for the newer version Ubuntu 21.04 (Hirsute Hippo).