Cryptocurrency exchange Bitget has confirmed that a zero-day vulnerability in a third-party security product was exploited in the recent theft of $387.5 million. Investigations by SlowMist identified malicious activity involving these third-party products and a customized tool used by the attackers. This incident highlights the significant supply chain risks associated with integrating external security solutions, especially in high-value environments like cryptocurrency exchanges. The ongoing investigation aims to uncover further details about the attack vector and the specific zero-day exploited.