Coldcard's 4th Wave Just Hit 462 Addresses-Another 460 BTC on the Move

Coldcard's fourth wave is still sweeping funds

The Coldcard exploit is still active. The latest wave hit 462 suspected victim addresses across 218 transactions in about 2.5 hours, sweeping roughly 389 BTC, with more transactions possibly pending.

Why the latest wave still matters

This keeps the risk front and center for anyone still using a Coldcard seed created before the patch. The first major wave already drained 1,082.65 BTC worth about $70.2 million from 1,196 Bitcoin addresses in 41 minutes. Later updates put losses at roughly $88.6 million across 4,585 addresses, and broader coverage now describes the total as over $90 million in Bitcoin stolen.

The vulnerability stays live as long as old seeds are still in use

The critical point is simple: patched firmware protects newly generated seeds, but it does not repair a seed created on vulnerable firmware. Even if some flagged addresses turn out not to be stolen, the practical takeaway for holders is the same-funds tied to exposed seeds are still at risk until they are moved.

Why bad randomness keeps Coldcard users exposed

The flaw turned seed generation into an offline problem

This was not a remote hack of a live device. It was a March 2021 firmware integration error that routed seed generation to a deterministic software PRNG instead of the STM32 hardware RNG. That changes the whole threat model: if seed generation can be narrowed down offline, the attacker does not need live access to the wallet.

Disclosure did not make weak seeds safe

According to Block, an attacker who can constrain the device UID, timer state, and prior RNG-call history can reproduce candidate output streams offline, derive addresses, and match them against public blockchain data. That is why the threat has persisted since disclosure.

No public report has reconstructed a victim seed and matched it to a drained address, but that absence of proof is not the same as safety for holders. For anyone still holding from a vulnerable Coldcard seed, migration remains the only reliable fix.

The patch protects new seeds, not old ones

Coinkite's emergency firmware matters, but it only protects what comes next. Installing it does not repair an existing seed, and restoring the old seed to updated firmware-or to another wallet-carries the weakness forward. The exposure is tied to the firmware that was running when the seed was created, not the version currently on the device.

Fourth-wave behavior shows broader targeting and faster sweeps

The attacker is using fresh destinations instead of one collection wallet

The latest pattern points to 216 fresh destinations tied to 462 victim addresses, with a fresh destination created for each victim rather than sending funds to a single collection address. That makes the activity harder to trace in a single bucket and suggests the operation is scaling across many targets.

Sweep speed is still unusually high

Galaxy observed 13.8 sweeps per block, around 45 times the rate seen in a pre-incident control window. Regardless of minor baseline differences between reports, the activity was still dramatically faster than normal. That points to an automated sweep process running at scale.

The target set appears to be widening

Galaxy said the attacker is targeting smaller balances and changing how funds are collected onchain. Some funds have already moved to second-hop addresses, which could indicate an effort to disperse proceeds faster.

That does not mean every flagged address is confirmed stolen. Thorn described the pattern as LIKELY Coldcard victims. Even so, the behavior still reads as an active exploit rather than a closed incident.

What to watch next

• Similar transactions remain pending in the mempool, so additional confirmations could still extend the wave.
• RBF opt-in has been signaled, meaning some eligible users may still be able to broadcast a higher-fee transaction to front-run a sweep.
• Ongoing creation of fresh destinations, rather than consolidation into one wallet, suggests the operation is still functioning rather than collapsing.