There is this video:
[video=youtube;WJ7iCcoft8Y]https://www.youtube.com/watch?v=WJ7iCcoft8Y[/video]
It's the only thing I was ever able to find on regrade hacking/exploiting - however, I highly doubt it is both still possible nor real. The software shown in the video resembles "fake programs" people usually use to trick people (primarily on YouTube) into downloading, and then infecting their computer with malware in order to hijack account information. However, the video gives no detail on any type of downloading. It appears to be simply an instructional video for that person's guild. Based on my experience in game hacking, what the software is doing in this video (the concept) is actually probably quite possible (or may have been at that time).
Again, this video is super old, but the concept of packet manipulation may be the only way of doing such a thing. Would you want to do that though? Likely not. It'd ruin the game and its economy pretty badly.