388.93 BTC Involved in Suspected Fourth Wave of Coldcard Attack, 462 Addresses Affected

Odaily News: According to monitoring by Galaxy's Head of Research, a suspected organized Coldcard attack is underway, with similar transactions still in the mempool awaiting confirmation. Previously confirmed transactions show RBF (Replace-By-Fee) enabled. Between blocks 960,778 and 960,792, 218 transactions occurred within approximately 2.5 hours, involving 462 victim addresses, 216 new destination addresses, and 388.92748828 BTC. None of the transactions had inputs predating the Coldcard firmware boundary. The sweep rate during this period was 13.8 times per block, compared to a baseline of 0.3 times per block in the pre-incident control window—approximately 45 times higher. The transaction topology is 1:1, with each victim address corresponding to a single new destination address. Only one destination address received two sweeps, and no consolidation addresses were observed. Some funds have already been swept to second-hop addresses.