Inside job of course
After translation from google, seems that a Chinese exchange called 796 was hacked out of 1,000 BTC,
by hackers switching the deposit (or withdrawal) address.. or something to that effect."... after detailed analysis of various logs and audit records, we found the system to update a few days ago the existence of sub-module exploited by hackers, causing the user to mention the current address has been tampered with, coupled with hackers deliberately used a similar address with the original withdrawals address to confuse users and our manual review."
Here is the google translation link I used.
https://translate.google.com/translate?hl=en&sl=zh-CN&tl=en&u=http%3A%2F%2F8btc.com%2Fthread-13689-1-1.html&sandbox=1According to this it was hackers switching the withdrawal/deposit addresses on the site. So they couldn't control how much Bitcoin was sent to the "hacker's" wallet. Regardless, I doubt it was some hacker. Logically speaking, why would a hacker gain so much to a site just to switch the withdrawal address. Doesn't make sense to not just steal the BTC from the hot wallet of the exchange when a change in deposit/withdrawal addresses could easily be found and fixed (or so I thought).