Ubuntu is beginning to be used by pure 'users' who don't know and don't care how computers work. These users are certainly not capable of securing their own systems.
Inevitably, we are going to have trojans and viruses.
I think some low hanging fruit could be picked off rather trivially. We could have a program that looks for common mis-configurations. It could clearly explain the problem, why it is a problem, and allows users to 'click-me' to fix (if there is a simple solution).
This would be a great addition to Ubuntu or any gnu/linux aimed at new users.
This could be configured on new installs on first logon. Users could use options like "enable firewall with common options" by default, disabled or customize. This could also be used to offer a short introduction to securing your OS (skip-able). You could also have "Install Clamav and enable regular scans" as an option.
The system could have a simple and advanced mode. Simple mode could change the language used to simplify any technical wording for novice users. Where as advanced would explain functionality more clearly using technical terms and offer more control.
Please don't hackup you own tool. Contect the dev's of Tiger and work togather with them. PLEASE Tiger is a nice tool but it leaks on devs and support. Last release was published in september 2007.