Coldcard Bitcoin Wallet Maker Compromised Again, This Time Online

The official X account of Bitcoin hardware wallet manufacturer Coldcard was compromised. On October 11, 2026, attackers published a fake notice in the brand’s name claiming a “critical firmware vulnerability” affecting the Mk4, Mk5, and Q models and urging users to move their funds immediately through a phishing website. The post appeared amid unprecedented anxiety in the crypto community . Hackers exploited the context of the brand’s recent disaster to make the scam more convincing. The post was subsequently deleted. The reason is that Coldcard experienced the biggest crisis in its history in late July 2026.