Coldcard Mk3 Vulnerability May Have Left Users Exposed to Hackers

A critical security vulnerability in some Coldcard Mk3 devices may have left users of Bitcoin hardware wallet manufacturer Coinkite at risk. The company has warned that seed expressions generated on these devices could be compromised, potentially putting associated Bitcoin addresses in danger.

The issue affects firmware versions 4.0.1 to 5.0.3 and was discovered amid an ongoing investigation into a large-scale attack in which hackers stole approximately $70.2 million worth of BTC from hundreds of single-signature wallets.

Galaxy Research's analysis suggests that the attackers may have used an automated tool to scan compromised private keys, emptying 1,196 wallets in just 41 minutes on July 30th. The stolen Bitcoins were consolidated into four different addresses, with no activity observed from these addresses since the transaction.