Breaking: Bitcoin cold wallet attack spreads to 4,500 addresses, with losses nearing $89 million. The attack stems from a vulnerability in the 2021 Coldcard firmware; hackers exploit weak randomness to replicate private keys. Three rounds of sweeping have been launched and it is now shifting toward low-balance accounts. ⚠️ Check your private key source and beware of risks from old firmware. #比特币安全 #冷钱包 #Encryption risk