Actually... once a worm has scanned a few wab, *.eml, *.htm, & other various documents/text files... or hell you could even check the clipboard for things. Anyways anyways... you'll want to look for .du .ru .com on the end of the addresses. You could make it change the language of the body & subject. You could make an entire array of phrases in those languages and produce random sentences like that.

All in all just check out the program known as Eliza... it does nothing but wait for input from the user and then ask a bunch of dumb questions that a therapist would normally ask along with the random but very occasional "Humm... I see" fallowed by another question. The big difference with mass mailers is the user isn't aware that information is being taken and stored in some place on their hard drive and is being used to contact other end users. Many if not most IRC worms could be compaired to very lame and watered down versions of AliceBot.

Agian the methods are just like some of the more older and redundant AI programs... you know, gain input from a user fallowed by an automated response. I mean really thats what AI currently is & has always been in many ways.