D'CENT and Trezor said they have faced security incidents involving software wallets and vendor systems. According to NS3.AI, the incidents included the export of 347,149 Trezor customer email contacts, while D'CENT is investigating unauthorized transfers from users of its software-based App Wallet.

Trezor said attackers used the exposed contacts to send phishing messages that reached about 2,500 recipients. Neither company has reported a compromise of its hardware-wallet security.