Earlier on Wednesday, more than $4.3 million was stolen from various tokens of Bitcoin DeFi app ALEX Lab after a suspected private key leak attacked its bridging service, Golden Finance reported. CertiK said the attackers may have obtained the private keys that control ALEX’s XLink bridge, a service that allows users to transfer tokens between different blockchains. The hackers moved over $300,000 worth of Bitcoin, $3.3 million worth of stablecoins, and $75,000 worth of Sugar Kingdom (SKO) tokens. ALEX developers confirmed the hack in an X post in the early hours of European time, claiming they knew the identity of the attacker. The team offered them a 10% bounty to return 90% of the stolen funds.