Mandriva One is a subset of Mandriva 2007. You pick and choose whether you want KDE, GNOME and various languages. The whole Mandriva 2007 release would never fit on a live cd so many packages are missing from the live cd.
If you need extra Mandriva apps, then go to
easyurpmi and setup the main, contrib, plf and updates repos for Mandriva 2007. After that use urpmi or the gui software package manager to install and remove software as well as update your software repos.
You can use clamav or avg for Linux. If you are not sharing files with Windows users, then there is no point in installing antivirus software on Linux.