we have just finished a phase of our ICO and we were looking among the transactions. Someone managed to send 0 ETH to our contract and in return got 130 000 tokens. How did he do that and how vulnerable is our system?
This is the holder with our tokens: https://etherscan.io/token/0x9a9ae6884c65725c8f5378dbb6d3900bff36da53?a=0x2bf6064d8fdb75af047d3db4743d436adb326312
These are his transactions. He seems to have created his own contract and he has done the same to someone else: https://etherscan.io/address/0x2bf6064d8fdb75af047d3db4743d436adb326312