Install and Automatic upgrade CAVL to new program version

Hi. I have a need to examine certain files with antivirus software, before forwarding them to the network before uploading them to a server, and I’m working on Ubuntu 14.04 LTS. I want my antivirus program after I upgraded to the new software version of the repository or through a module to automatically update the entire Ubuntu operating system. So, I know that antivirus database updating through their own program, but I’m concerned about upgrading the software to the new version that is somehow automatic. I apologize for the bad English because I use google translate. How to properly install and add the repositories and how to program after upgrading to new versions?