← SecurityChecked 2026-10-13

Hardware wallet implant and the Coldcard entropy bug

In plain words: what Ledger confirmed, what is only reported so far, what the Coldcard bug was, and what to do now. With links to sources.

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Hardware Wallet Implant & Weak Entropy: What To Do

What Ledger confirmed about the implant in devices sold by CryptoBilis, what is only reported, the Coldcard entropy bug, and four steps: verify firmware, add dice entropy, never type your seed online, buy from the official store. Not investment advice.

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What Ledger confirmed

On October 10, 2026, Ledger confirmed that one affected user's device contained an unauthorized hardware implant.
The affected devices were sold by CryptoBilis, a reseller in Southeast Asia. Ledger says all confirmed losses from the incident disclosed on October 9 involve devices sold through CryptoBilis. CryptoBilis stopped selling Ledger devices during the investigation.
How it worked, according to Ledger: the implant sits inside the case and reads what is shown on the screen. During setup the device shows the 24-word recovery phrase. The implant decodes those words and sends them out over LTE (a mobile network) using an eSIM.
Ledger says the implant is a separate component. It did not modify the Secure Element chip or the Ledger operating system, and it did not change transactions or signatures.

What is only reported so far

Researchers reported tampered devices bought at MediaMarkt stores in Europe. Ledger says it has not verified a theft linked to a device bought elsewhere and is examining these reports.
Researchers reported the implant in Ledger Nano X devices, in two versions. Ledger has not publicly named the model.
Estimates of total losses differ between sources (from about $86M to about $102M). These are on-chain estimates, not confirmed figures.

The Coldcard entropy bug (July 2026, fixed)

In July 2026 Coinkite disclosed a firmware bug: seed generation used a predictable software random number generator instead of the hardware one. Attackers recreated the weak keys offline and stole funds. Coinkite says the devices themselves were not hacked or remotely accessed.
Affected: Mk2 and Mk3 on firmware 4.0.1 through 4.1.9; Mk4 and Mk5 before 5.6.0 (Edge before 6.6.0X); Q before 1.5.0Q (Edge before 6.6.0QX). On Mk4, Mk5 and Q the effect is weaker (about 72 bits instead of 128) but still serious.
Fixed: Mk2/Mk3 4.2.0 or later; Mk4/Mk5 5.6.0 or later (recommended now: 5.6.3); Q 1.5.0Q or later (recommended now: 1.5.3Q).
Updating does not repair an old seed. Seeds made on affected firmware must be replaced and funds moved, unless the seed was made with at least 50 private dice rolls and the wallet has a strong, unique passphrase.

What to do now

Bought a Ledger from CryptoBilis? Do not set up an unused device. If you already use one, move funds to a new device with a new recovery phrase, and do not restore the old phrase on the CryptoBilis device (Ledger's advice).
Have a Coldcard? Check which firmware created your seed. If it is in the affected range, update first, then make a new seed and move funds.
Keep firmware updated and use the maker's tools to check the device is genuine.
When you create a new seed, consider adding your own dice rolls as extra entropy.
Never type your seed phrase into a website, an app or a chat. Real support never asks for it.
Buy hardware wallets only from the official store, and do not use a device from an unknown seller or one that looks opened.
For larger amounts, many experts suggest not relying on a single device, for example with multisig.

Sources

Not investment advice. This page summarizes public statements and reports; unconfirmed points are marked as such.