Coldcard hack enters fourth wave, losses may rise to $114M

A code flaw in Bitcoin hardware wallet maker Coldcard has led to the theft of about 1,367 BTC, and a fourth attack is now underway that could push cumulative losses to 1,816 BTC, or $114 million, CoinDesk reported. Galaxy Research's Alex Thorn explained the hacker is using replace-by-fee, allowing the attacker to pay a higher fee and move the funds first if victims confirm unconfirmed transactions. Earlier, Coldcard had already suffered thefts of more than 1,359.88 BTC tied to a random number generation flaw, while some devices were also reported to have been bricked by an emergency firmware release.