Smart Contract hacked and fund stolen

Hi, There is something unusual happened with the project which have been working fine.

This is the contract

5 days back, the contract is hacked and fund transferred.

Before that 13 days ago, some one has tried to do same but couldn't succeed.

Anybody help me to explain how this could have happened?

Is it possible to identify the hacker?

Drop your codebase let me run a test on it

you can connect me on twitter @ighodarod95

The contract address is this - 0x4d1a3e3172e0e76b417dc304a6855c67c5e21f6f

the fund i traced is till this address
0xb0e779e5c48c0c40faec7964f86f8159e3c48584