A hacker targeted a vulnerability in DeFi protocol Ankr to mint trillions of aBNBc tokens, which he eventually swapped for 5 million USDC.The event caused the price of aBNBc to plummet by 99%, which allowed another individual to steal $15.5 million from stablecoin issuer Helio as it did not have up-to-date pricing on aBNBc.