The AutoStart Worm is a worm that can be spread to your computer when you have an infected CD and QuickTime is set to "Autoplay" CDs. The Macworld CDs are checked for infection at three levels. They are checked by the developer, the quality assurance team, and during replication and are not distributed with viruses or worms.
If you are still concerned about using the Macworld CD, please note that it is impossible for this worm to spread to your computer if ?Autoplay? is disabled. To disable Autoplay, go to your QuickTime Control Panel and uncheck Autoplay if it is checked.