Hi, the operation of scam is not withrawals but it is buy at hight price then sell low, many orders with this way until no enath credit to trade
Api key that utilise in tab trader have all permission read trade and withdraw
Part from bittrex answer:
(This account shows that buy high sell low trades were made using your API keys. Please make sure to delete your API keys. Do you know what third party site had access to your keys?)