According to CoinMeta, a firmware vulnerability in coldcard in 2021 led to insufficient randomness in seed recovery, allowing attackers to transfer between 1,600 and 1,800 Bitcoins from affected wallets since July 30, with an estimated value of over $100 million. Coinkite suggests that it is necessary to assume that someone has exploited this vulnerability to review the public firmware. Researchers at Shielded Labs discovered a flaw in the zcash shielding pool that began in 2022; during tests, it was possible to generate forged ZEC. Developers have since completed the fix. Chainalysis statistics show that the average number of on-chain writes carrying malware instructions increased from 2.06 times per day to 11.1 times per day.