Threat intel

Trezor told customers on October 30, 2026 to move their funds if they bought any Trezor hardware wallet from CryptoBilis, a Southeast Asian reseller, from March 2026 onwards. Two days earlier a buyer in Indonesia had reported, through Trezor's responsible disclosure programme, an extra circuit board inside a Trezor Safe 5 that he bought from CryptoBilis in August 2026 through the reseller's store on Tokopedia, an Indonesian e-commerce marketplace. The board reportedly carries a cellular module and an antenna and sends out the wallet backup shown on the screen.

Trezor had not examined the device when it published the warning. It said it was treating the report as credible from the customer's photos and a video interview, because waiting for lab results would leave CryptoBilis buyers exposed in the meantime. No CryptoBilis buyer has reported a loss to Trezor, and the reporting customer had already moved his funds before he found the board. If your company holds crypto on a Trezor and you cannot say who sold it, check the receipt today.

How it works

A Trezor Safe 5 keeps its keys behind an OPTIGA secure element, a tamper-resistant chip. When you create a wallet, the device generates a recovery phrase (the seed, also called the wallet backup) and shows the words on its touchscreen so you can write them down. Anyone who has those words can rebuild every key on another wallet, without the device or its PIN.

According to the report, which Trezor says it has not yet verified, the implant sits between the Safe 5's main board and its screen. It reads what the screen shows, including the backup words, and transmits them over a mobile network whenever the device is plugged in. Because it has its own modem, it needs no help from the computer, the USB link or Trezor Suite. Trezor says it appears to work like the implants found in Ledger devices sold through the same reseller, which we covered in our post on the Ledger case, but it declines to compare the two in detail while investigations continue.

The checks a buyer can run were not designed for this. Trezor's device authentication check has Trezor Suite send a random challenge, which the secure element signs with a certificate installed at the factory; Suite then verifies the signature and the certificate. The bootloader separately refuses firmware not signed by SatoshiLabs, the company behind Trezor. Both prove that the chip and the code are genuine. An added board that only watches the display leaves both untouched, so a passing check does not clear a CryptoBilis unit. Trezor has not said whether either check would flag this implant.

Physical inspection does not settle it either. The reporter noticed a weight difference, but Trezor says small differences have other causes, so a scale can neither confirm nor rule out tampering, and it asks owners not to open or weigh their devices.

What we know about the attack

The timeline starts with Ledger. On October 9, after Ledger began investigating thefts from customers who had bought through CryptoBilis, Trezor removed CryptoBilis from its reseller network as a precaution. On October 13 it went further, telling some other resellers that their authorisation ends on January 1, 2027; they stop receiving new stock now and can sell what they hold until then. Trezor has not named them or said how many there are.

Since October 9 Trezor has inspected Trezor devices that customers bought from CryptoBilis. It found no signs of tampering on any of the four it had received by October 30. One outlet describes those four as Safe 5 units; Trezor's own post does not give the models. The August Safe 5 is the only reported Trezor case, and Trezor says it has no reports involving any other reseller or region.

Who built the implant, how many units carry it, and whether the same people are behind the Ledger thefts are all unknown. Trezor credits SEAL 911, the Security Alliance's emergency response service for crypto incidents, with helping on the report. Trezor is arranging for the device to be sent to its lab, so the technical picture may change once it has been examined.

What to do

Start with the receipt. Trezor's notice covers any store that sold devices supplied by CryptoBilis, including its Tokopedia store, so the platform name alone does not tell you. Look for CryptoBilis as the seller, or ask Trezor Support through the chat at trezor.io/support.

If a CryptoBilis device is in use, create a brand new wallet with a new backup on a different, trusted device and move everything to it. Restoring the old words on a new Trezor does not help, because the old words are what may have leaked. If no other hardware wallet is available, Trezor says to use a software wallet or an exchange you already trust for now, and to check the full receiving address before sending. Move the largest balances first, chain by chain.

If the device is still unopened, do not set it up, and never type an existing backup into it. Keep the unit either way: Trezor will send a free replacement directly or give a voucher to any CryptoBilis customer who bought from March 2026 onwards.

To see whether you were already hit, look up every address under the old backup in a block explorer for outgoing transfers you did not make. Do not import the old words into any app to check. Expect phishing that uses this incident: Trezor says its support will never ask for your backup, by email, letter or phone.

For a company, list each signing device with its model, serial number, seller and purchase date, and replace anything that did not come from the manufacturer's own shop or a seller you can verify on its reseller list at the time of purchase.

Buying signing devices

Trezor's own buying checks are to buy from the Trezor shop, its official Amazon storefront or a listed reseller, to confirm the holographic seal over the USB-C port is intact, and to reject any device that arrives with firmware already installed. Run the authenticity check in official Trezor Suite. None of these is designed to find a board added inside an otherwise genuine device, which is why Trezor is shrinking its reseller list. Treat the purchase channel as part of the device's security, and for treasury amounts use multisig across devices from different makers, so one tampered unit cannot move funds alone.

Our safeguarding and hardening work covers key custody and how signing devices are bought and set up, and our security operations team can watch treasury addresses for transfers nobody approved. Open the chat and Yaali, our AI agent, will pass your question to an engineer.

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Sources: Trezor: Implant reported in a Trezor sold by CryptoBilis, Trezor: Is my device safe to use?, Trezor: Safe device authentication check, Trezor: Authenticate Trezor Safe 5, Unchained, The Block, Decrypt, BleepingComputer, Bitbo, Decrypt: Trezor cuts its resellers, CryptoTicker.