South Korea's National Tax Service (NTS) inadvertently revealed a cryptocurrency wallet seed phrase in an official press release, resulting in the loss of approximately $4.8 million in Pre-Retogeum (PRTG) tokens. The press release, detailing enforcement actions against tax delinquents, included an image of a cold wallet and the unmasked mnemonic phrase. Blockchain researchers identified the compromised wallet, which briefly held the 4 million PRTG tokens before they were transferred to another address. An associate professor from Hansung University’s Blockchain Research Center confirmed the theft, noting that while the stolen tokens are difficult to liquidate, the incident highlights significant security lapses.
This event follows other recent crypto custody issues in South Korea. In February 2026, police discovered that 22 Bitcoin seized in a hacking investigation had disappeared from a cold wallet. Separately, regulators are facing pressure over a large trading error on the Bithumb exchange and the Financial Services Commission's oversight.