First, are you familar with magelo autoupdater? It scans your char, and it sees your bank. Why? Because your bank is part of your char, everything in your bank is in your char, and that is why any npc can be a banker. However, other people's chars, are different files on the server and thus, have access rights based on flags. Previously, there was a flag added to a corpse, to allow access. Those rights have been removed (for obvious reasons).
I don't imagine any client side hack, that would send the information to the server making it think the user is the owner of the file (corpse).
Oh, and did you say legit?