That being the case, this would be more of a virus and not worm. However, some of these malicious AIM-related activities can be more defined as 'trojans'. I'd concider a worm to be something which spreads just by a computer user with a vulnerable version of the program, so that they can get infected without downloading and/or running outside files.
If it infected the AOL executable so that every time you ran AOL it sent itself out, that's a virus.
If it was a program that you ran, and it looked like a game, but it was really spreading secretly, then it's a trojan.
The way it sits, it's a worm. The same way Netsky and Mydoom and Bagel are worms.
