The Tapioca Foundation has offered a $1 million bounty to an attacker who stole $4.7 million from its decentralized finance protocol in what it has called a “social engineering attack.” “We would like to offer you an attractive bounty settlement where you would walk away with funds that are fully legally yours, no strings attached,” Tapioca wrote in an Oct. 20 onchain message to the attacker’s crypto wallet. It offered $1 million in Tether (USDT) — which it said was “significantly higher than the normal 10%” offered in bounties — in exchange for the attacker returning the remaining $3.7 millio…