TechFlow news, August 9 — According to Cointelegraph, security researchers have discovered an attack mechanism dubbed "Dark Skippy," which enables hackers to extract private keys from Bitcoin hardware wallets using just two signed transactions. This vulnerability could potentially affect all hardware wallet models, but only if attackers successfully trick users into downloading malicious firmware.
The research report was published on August 5 by Lloyd Fournier and Nick Farrow, co-founders of Frostsnap, along with Robin Linus, a co-developer of the Bitcoin protocols ZeroSync and BitVM. The report reveals that a hardware wallet's firmware can be programmed to embed portions of a user's recovery phrase into "low-entropy secret nonces" used during transaction signing. Once transactions are confirmed and their signatures published on the blockchain, attackers can scan and record these signatures to reconstruct the private key.
Past vulnerabilities in Bitcoin wallets have led to significant user losses. In August 2023, SlowMist reported that over $900,000 worth of Bitcoin was stolen due to a flaw in the Libbitcoin explorer library. In November, Unciphered warned that $2.1 billion worth of Bitcoin might be at risk of theft due to a vulnerability in the BitcoinJS wallet software.
