Possible Nexon Database Exploit?

Have you consider another student that have access to the same wireless network can monitor all the traffic could be the one that hacked you? Also even if one doesn't have proper access to the "protect" wireless network, they can still monitor and crack the encryption without getting connected to the router.
You don't have to download anything out of the ordinary, as a lot of web sites have pfd/flash docs embedded into them. Just clicking on a simply link can trigger Adobe. Too quick to "busted"!

That other student would need to know that I play Maplestory, and also who I am, wouldn't they? That seems a little far-fetched, to be honest.

Most, if not all, of the sites I got to are college-related. If someone managed to get a key logger into any of the documents that are on my university's server, then kudos to them as I've stated before. I highly doubt it, however.