A smart contract which holds Ether and needs a permisssion of a specific address like owner to allow for performing transactions shall always check msg.sender instead of tx.origin.

In a few cases, it may happen that an attacker would create a contract like Attack.sol in this project and somehow make the victim Owner of EtherBank.sol to send a transaction to an address.

Now you may know this that if victim send a transaction with enough gas to a contract assuming of just an address since etherscan doesn't display contracts by default which is having a fallback(), it may re-direct your call and perform malicious activity.

In our project, attack function was called from Attack.sol but when it reaches EtherBank.sol, the tx.origin is the one who initiated the transaction which is victim.

This way Phishing attacks steals Ether from a contract with such functionality.

In most cases, use msg.sender instead of tx.origin for condition checks as it will detect the read address which called the function.