An attacker drained 1,196 Bitcoin addresses in 41 minutes on July 30, taking 1,082.65 BTC worth about $70.2 million at the time. Galaxy Research mapped the sweep and tied it to a firmware flaw in Coldcard, the Bitcoin-only hardware wallet made by Canadian firm Coinkite. A March 2021 firmware integration error routed seed generation to a deterministic software pseudorandom number generator (PRNG) instead of the STM32 hardware random number generator (RNG). Block says an attacker who can determine or sufficiently constrain the device UID, timer state, and prior RNG-call history can reproduce candidate output streams offline without accessing the device. Candidate seeds can then be checked by deriving their addresses and comparing them with public blockchain data. Coinkite shipped emergency firmware for every affected model and release track on July 31, but installing it does not repair an existing seed. Coinkite tells owners with exposed seeds to generate a new one on patched firmware and move their coins. Restoring the old seed to updated firmware or another wallet carries the weakness forward. No public report has reconstructed a victim's seed and matched it to a drained address. Block traced the fault to Coldcard's production config, which defines MICROPY_HW_ENABLE_RNG as zero because Coinkite supplies its own hardware-RNG wrapper. The libngu library checked whether the macro existed rather than whether it was enabled, binding the build to MicroPython's Yasmarang fallback. The MicroPython fallback was initialized from the chip's unique ID and timer registers and collected no fresh entropy after initialization. Coinkite estimates effective entropy at roughly 40 bits on the Mk3 and about 72 bits on the Mk4, Mk5 and Q, against 128 bits for a 12-word BIP-39 seed. Block does not give one practical figure. It sets conditional ceilings below 240.7 and 273.3 and warns that the latter is not equivalent