The special part about this exploit was the obfuscation and “hidden payload” within the BIP which has not been previously seen in the wild; at least not in this way. The exploiter used a flash loan to borrow the voting power needed to push the proposal into emergency action via a bean purchase and deposit, and then ALSO triggered a withdrawal of funds in an exit call hidden within the BIP. Since a flash loan completes in a single block, the theoretical BEAN was non-existent, but it allowed the attacker to exit with “his share” of the protocol which was heavily inflated. Using this method the attacker tricked the protocol into relieving the ENTIRE liquidity provisions of the stable since he was theoretically entitled to those funds after depositing into all three pools on the BEAN platform and then exiting which pulled out all the liquidity in those pools. (LUSD,3CRV,BEAN/ETH LP) Once the transaction was over and the funds were removed that were previously deposited, less than 0.25% of the initial liquidity remained.