There is a possibility of using Macintoshes running OS8.6+ to create denial-of-service network attacks. The MacOS has a 'feature' whereby a particular small ICMP packet sent to it will elicit a large reply packet. Combined with address spoofing, this amplification can be used to 'bomb' a network by remote control.

SOLUTION:

Apple has made available an extension called "Open Transport Tuner" which disables the 'feature'. It is available at

http://asu.info.apple.com/swupdates.nsf/artnum/n11559