Coldcard hardware wallets wiped out in 15 minutes: 594 BTC native According to @lookonchain monitoring: One of the most severe hardware wallet thefts in Bitcoin history—approximately 500 single-signature wallets were completely emptied within just 15 to 25 minutes, totaling 594.48 BTC (approximately $38.2 million), with all funds consolidated into a single address. The root cause is a critical flaw in the Coldcard Mk3 (and certain early firmware versions): since firmware version 4.0.1 in March 2021, the seed generation entropy was reduced to only about 72 bits—far below the standard 128 bits—resulting in severely insufficient randomness, making private keys vulnerable to brute-force attacks. Official vendor Coinkite has issued an urgent security alert: If you ever generated a seed using an affected device (especially without a BIP-39 passphrases), your funds are at immediate risk of theft.