Bitcoin cold-wallet exploit hits 4,500 addresses with losses approaching $89M

A sophisticated attack targeting weakly generated Coldcard wallet keys has expanded to 4,500 Bitcoin addresses, with total losses nearing $89 million. Galaxy Research identified a third wave of fund sweeps linked to the same vulnerability, signaling the attack is ongoing and escalating. The attacker has shifted strategy, now targeting wallets with smaller balances that were previously overlooked. Additionally, the method used to consolidate stolen funds onchain has changed, suggesting the perpetrator is adapting tactics. The root cause appears to be cryptographic weaknesses in keys generated by Coldcard hardware wallets.