There are no extra transactions in kobocoin blockchain at the time of the hack, think have to be relieved about that because they took more than first appeared and it can be a coin killer if they get hold of a majority share, some never recover from that.

Can remember when Cryptsy got hit, Big Vern said that the way they did it was inserting a few lines of code in the github source code for a coin update, and slipped in that way, hard or impossible to stop if you're accept lots of coins because its unlikely the exchange will be checking over thousands of lines of code for something that is designed not to set off the virus scanners.