Address poisoning is a technique where scammers create vanity addresses that mimic legitimate addresses that a wallet with high net worth interacts with. In this case, the attacker likely created a fake address that resembled the victim's address, leading the victim to mistakenly send a large amount of funds to the exploiter. The attacker has already moved the stolen WBTC to different wallets and is converting the funds to Wrapped Ether (WETH