Covert hardware implanted in some Ledger crypto wallet devices sold by Southeast Asian reseller CryptoBilis read users’ 24-word recovery phrases from the gadget screen and sent them to an attacker over a mobile phone network, Ledger said Tuesday in an investigation update on X.
Ledger said the spy chip sat inside the device enclosure. When a user set up the signer and the screen displayed the recovery phrase, the implant’s microcontroller recognized and decoded the words, then transmitted them over LTE, a data transmission technology used by cellphones, utilizing an eSIM.
The recovery phrase is the master key to a crypto wallet. Anyone who has it can recreate the wallet elsewhere and move the funds without needing the physical Ledger device or changing any transactions on it.
The account is the first public explanation of the mechanism behind the CryptoBilis-linked thefts. Ledger said the implant did not modify the device’s secure Element, the chip designed to protect private keys, or its operating system. It also did not alter transactions or signatures. The incident was a physical supply chain attack rather than a breach of Ledger’s software or internal systems.