Coldcard Wallets Hacked for $70 Million in Record-Breaking Bitcoin Heist

A severe Bitcoin security breach has occurred, according to Strike CEO Jack Mallers, who described it as 'one of the most serious' in Bitcoin's history. The exploit targeted Coldcard wallets, which are considered secure because they use hardware random number generators (RNGs) to create wallet seeds.

However, Block's engineering team discovered a firmware bug dating back to March 2021 that caused certain Coldcard devices to default to a weak software RNG instead of the hardware one. This allowed hackers to steal over $70 million worth of BTC from 1,196 addresses within just 41 minutes using an automated tool.

Mallers warned users not to simply put compromised seeds back onto new wallets, as this would not resolve the issue. Instead, he recommended moving funds to newly created wallets on unaffected hardware and offered Strike as a temporary exchange option for impacted users.

Binance co-founder Changpeng Zhao also weighed in, stating that 'even hardware wallets can have bugs' and suggesting users consider diversifying their funds across multiple wallets as a mitigation strategy.