NOTE - Some code has been slightly altered to work with newer versions of solidity and enable us to test the level with foundry. Any where this has been done an accompanying comment gives context for why this change was made.
Original Level
https://ethernaut.openzeppelin.com/level/0x9CB391dbcD447E645D6Cb55dE6ca23164130D008
https://hackernoon.com/ethernaut-lvl-1-walkthrough-how-to-abuse-the-fallback-function-118057b68b56
forge test --match-contract FallbackTest -vvvv