Clam AntiVirus (ClamAV) is a free, cross-platform and open-source antivirus software toolkit able to detect many types of malicious software, including viruses. One of its main uses is on mail servers as a server-side email virus scanner.
To do this on Ubuntu, you can open a terminal and insert “sudo apt-get installclamav” and press enter. You may also build ClamAV from sources to benefit from better scanning performance. To update the signatures, you type “sudo freshclam” on a terminal session and press enter. Now we are ready to scan our system.