On October 28, Trezor’s security team received a report through its responsible disclosure program. A buyer in Indonesia had found a foreign board inside his Trezor Safe 5: it sits between the main board and the screen and carries a cellular module and an antenna. According to the buyer, the board reads everything the screen displays, including the wallet backup — the seed phrase — and sends it out over the mobile network every time the device is plugged in. The wallet was bought in August from CryptoBilis — until October an official Trezor reseller in Southeast Asia — through its store on the Tokopedia marketplace.
Now for what has been confirmed. Trezor writes that it has not yet received the device itself and has not examined it in its lab. The company has a description, photos and a video interview with the buyer, and it found the report credible enough to warn customers without waiting for a lab analysis. No thefts among CryptoBilis buyers have been reported to the company so far. The finder himself had moved his money off the device before he discovered the board. Bottom line: one board in one wallet, and how exactly it works is known so far only from its owner’s words.
What to do if you bought your Trezor from CryptoBilis
If you bought a Trezor from CryptoBilis since March 2026 — directly, on Tokopedia or in a store it supplied — the company advises moving your funds to a new wallet with a new seed phrase as soon as possible. Restoring the old phrase on another device is pointless: if it has already been spied on, the thief’s copy won’t disappear. If you haven’t started using the device yet, it’s better not to set it up at all — and certainly never enter an existing phrase into it. Trezor promises a free replacement or a voucher and asks you to keep the CryptoBilis wallet itself, Help Net Security reports. The company advises against weighing or opening the device: there is no reliable way to check it yourself. And brace yourself for emails, calls and even paper letters “from support” — real Trezor support never asks for your seed phrase.
Why the scheme works at all
Nobody had to crack the secure chip or the firmware here. The implant simply relies on the fact that the wallet generates the seed phrase itself and shows it on its own screen. From there the scheme is simple: buy or intercept a batch of devices, open the case, solder in between the board and the display a module that reads the image and can get onto the mobile network, carefully reassemble, seal and sell through a channel as official as they come. Then wait for the buyer to copy the words from the screen onto the card in the box and load the wallet with money. Transaction signing, the chip, the app — everything works as it should. The screen has simply gained a second viewer. So the first question to ask before buying any wallet is whether it even has room for such a viewer: a device with no screen, no battery, no firmware and no USB has nowhere to plant an extra board, and nothing to power it with.
On first connection, Trezor checks the device’s authenticity using the secure chip and promises to confirm that it is “genuine and unmodified.” How the Indonesian board behaved during this check, the company hasn’t said yet. But “the chip is genuine” and “nothing was soldered next to it” are two different statements, and nobody hands the buyer an answer to the second question.
The flaws that make this kind of attack possible
- The device generates the seed phrase itself and displays it on its own screen. Whoever sees the screen sees the money.
- You can’t look inside. Trezor itself admits there is no reliable way to check the device yourself, and advises against opening it.
- The case has room for an extra board, and USB powers it every time you plug in.
- The heart of the protection is a closed secure element. Trezor’s firmware is open, but what exactly sits in your unit and what has been soldered to it, the buyer still can’t verify.
- The buyer has to trust everyone who has held the box: the factory, the warehouse, the distributor, the reseller, the marketplace and the courier. Official seller status, as it turns out, guarantees nothing.
- There is nothing to check the hardware with: scales, according to Trezor itself, prove nothing. What’s left is faith.
Hence a couple more questions worth asking before buying any wallet. Does the device arrive blank, so that you create and encrypt the key yourself, on your own phone — and then it no longer matters who held the box before you? Can you read what is stored on it with any NFC app and spread encrypted copies across several cheap tags, so you don’t have to pray to a single piece of hardware?
A hologram as a lucky charm
The holographic sticker deserves special admiration. On the Safe 5 it covers the USB port, the box is shrink-wrapped, and the instructions ask you to make sure the seal is intact, with no tears or traces of glue. Holograms these days are printed to order in batches, and re-wrapping a box in film is no great feat either. Most importantly, the implant has no reason to touch the port: it lives inside, between the board and the screen. The sticker honestly tells you exactly one thing: nobody has peeled it off. What’s under the lid, it doesn’t know and can’t know. It isn’t protection — it’s a sedative with a shimmer.
Trust both ways
In the end, the buyer relies on two mutually exclusive assumptions. The manufacturer is so much smarter than he is that it can be trusted with creating the keys itself. And everyone who touched the box along the way is more honest — or dumber — than a swap requires. Trezor now promises to tighten its vetting of resellers and cut their number. It’s the right step, but it only narrows the circle of those you have to trust; it doesn’t remove the need to trust.
But chasing CryptoBilis is like cutting off the hydra’s heads: shut down one store and three new ones grow in its place. The problem isn’t a bad seller but a scheme that needs an honest seller. Somewhere in your town, on a local marketplace or from a “trusted” flipper, wallets with implants may have been on sale for a long time, and nobody knows. This isn’t, after all, a German electronics megastore that security researchers drop into. The Indonesian board was found only because one buyer happened to be attentive and wrote to Trezor himself. How many buyers like that never turned up, nobody knows.
We recently reviewed Tangem and Mitilena — pros and cons included. If you don’t want to depend on whoever held the box before you, choose wallets where you create the key yourself and the device arrives blank: a card swapped along the way is then worthless — you simply write your own encrypted key onto it. Mitilena, for example.