The LegendaryMoneyMonNft contract’s cliamRewred function had a signature verification flaw. The verify() only checked if recoverSigner(...) == admin, without properly validating cases where ecrecover returns address(0). The attacker set admin to zero address, then used an invalid signature (r=0, s=0, v=27) to bypass checks, arbitrarily claim rewards, drain all tokens from the contract, and swap them for USDT via PancakeSwap.