If you run Mac OS 9, even if you're running it under the Classic environment
in X, you're vulnerable to a QuickTime-related security hole.
The best way to protect yourself is to turn off QuickTime AutoPlay functions
in the OS 9/Classic QuickTime Settings control panel--specifically, the
"Enable CD-ROM Autoplay" function. It's also a good idea to rename
your hard drive to something other than the default "Macintosh HD."
For details, see Ron Carlson's March 1st article "An old QT problem resurfaces as a security hole" on the IGM website at http://www.insanelygreatmac.com/news.php?id=84 and "Auto file execution vulnerability in Mac OS" at http://homepage.mac.com/vm_converter/mac_autoexec_vuln.html