#Coldcard漏洞被盗594枚BTC
About 594 bitcoins (worth about $38 million) were collectively transferred within a 25-minute window from 01:31 to 01:56 UTC on July 30, originating from approximately 500 independent wallets. Nearly all of these wallets were single-signature addresses, each holding more than 0.15 BTC; many had been dormant for years, with funds deposited across 2021 to 2026. Afterwards, about 562 BTC was consolidated to the same address and has not moved further yet. The issue lies with the Coldcard hardware wallet firmware. Starting with version 4.0.0 released in March 2021, the device skipped the true hardware random number generator when generating seeds and instead used a predictable software fallback. Effective entropy dropped from the expected 128 bits to about 40 bits (Mk3 model), making the private keys feasible to brute-force. The attacker clearly calculated these weak seeds in advance, then wiped the funds in one scripted sweep. Coinkite (Coldcard’s manufacturer) quickly issued a warning: seeds generated on Mk3 when running firmware 4.0.1 or higher may be affected. Updating the firmware itself cannot fix already-generated weak seeds—you must regenerate entirely new seeds and migrate the assets. Later analysis indicates that models such as Mk4, Q, and Mk5 may also have similar but less severe entropy shortfalls (around 72 bits). The company believes that because the source code has been open for a long time, attackers may have used AI to scan older firmware versions and discover this vulnerability—when they themselves rechecked with top-tier AI models, they couldn’t find the bug in advance either. The on-chain traces are very clear: high-fee transactions, no change outputs, and bulk transfers—typical of an automated sweep pattern. Initial tracking by security teams such as Block also linked some activity to blockchain service providers. Follow-up analysis by Galaxy Research and others expanded the related addresses to nearly 1,200, with the total amount possibly approaching 1080 BTC (about $70 million). However, the core vulnerability and the initial swept amount still center on 594 BTC. This incident is a loud slap in the face for the entire self-custody community. Hardware wallets are touted as “offline means safe,” but a build error at the firmware layer can lurk for five years—only to be harvested in one go once attackers are ready. Open source enables auditing, but it also gives adversaries equal code visibility—into the AI era, this imbalance is being amplified. Single-signature, long-dormant addresses are especially dangerous; using multisig or strong passphrases can significantly raise the barrier, but many people skip that for convenience.
About 594 bitcoins (worth about $38 million) were collectively transferred within a 25-minute window from 01:31 to 01:56 UTC on July 30, originating from approximately 500 independent wallets. Nearly all of these wallets were single-signature addresses, each holding more than 0.15 BTC; many had been dormant for years, with funds deposited across 2021 to 2026. Afterwards, about 562 BTC was consolidated to the same address and has not moved further yet. The issue lies with the Coldcard hardware wallet firmware. Starting with version 4.0.0 released in March 2021, the device skipped the true hardware random number generator when generating seeds and instead used a predictable software fallback. Effective entropy dropped from the expected 128 bits to about 40 bits (Mk3 model), making the private keys feasible to brute-force. The attacker clearly calculated these weak seeds in advance, then wiped the funds in one scripted sweep. Coinkite (Coldcard’s manufacturer) quickly issued a warning: seeds generated on Mk3 when running firmware 4.0.1 or higher may be affected. Updating the firmware itself cannot fix already-generated weak seeds—you must regenerate entirely new seeds and migrate the assets. Later analysis indicates that models such as Mk4, Q, and Mk5 may also have similar but less severe entropy shortfalls (around 72 bits). The company believes that because the source code has been open for a long time, attackers may have used AI to scan older firmware versions and discover this vulnerability—when they themselves rechecked with top-tier AI models, they couldn’t find the bug in advance either. The on-chain traces are very clear: high-fee transactions, no change outputs, and bulk transfers—typical of an automated sweep pattern. Initial tracking by security teams such as Block also linked some activity to blockchain service providers. Follow-up analysis by Galaxy Research and others expanded the related addresses to nearly 1,200, with the total amount possibly approaching 1080 BTC (about $70 million). However, the core vulnerability and the initial swept amount still center on 594 BTC. This incident is a loud slap in the face for the entire self-custody community. Hardware wallets are touted as “offline means safe,” but a build error at the firmware layer can lurk for five years—only to be harvested in one go once attackers are ready. Open source enables auditing, but it also gives adversaries equal code visibility—into the AI era, this imbalance is being amplified. Single-signature, long-dormant addresses are especially dangerous; using multisig or strong passphrases can significantly raise the barrier, but many people skip that for convenience.