A recent security incident involving tampered hardware wallets has led to reports of thefts totaling approximately $93 million. The issue came to light after Ledger confirmed that a device sold through its authorized Southeast Asian reseller, CryptoBilis, contained a hidden malicious implant.
Users have begun using kitchen scales to detect unauthorized hardware, such as extra circuit boards or cellular modems, by comparing device weight against manufacturer specifications. For instance, the Ledger Nano X is officially listed at 34 grams, while the Trezor Safe 3 weighs 14 grams.
Former Mt. Gox CEO Mark Karpelès discovered a spy chip in a sealed Ledger Nano X purchased in Malaysia. The implant was designed to capture recovery phrases from the screen and transmit them via a cellular connection. However, Karpelès noted that the added weight of such components can be minimal.
Karpelès observed that the weight difference caused by the implant in his unit was approximately one gram. This variance often falls within the range of normal factory tolerances, as components like batteries can differ in weight despite having identical capacities. Consequently, standard kitchen scales are insufficient for reliable detection.
Ledger has suspended sales through the affected reseller and advised recent customers of CryptoBilis to avoid setting up their devices. The company emphasizes that physical inspection of the internal board remains the only definitive method to ensure security, suggesting that purchasing directly from manufacturers is the safest practice.
