French Authorities Investigate Data Breach at Crypto Tax Platform Waltio

French law enforcement has opened a preliminary investigation into a security breach at Waltio, a cryptocurrency tax reporting service, after a hacker collective known as Shiny Hunters claimed responsibility for stealing user data and demanded payment from the company.

According to authorities' Thursday announcement, the Paris Public Prosecutor's Office and National Cyber Unit are working to determine the scope of compromised information and identify affected users. The breach reportedly exposed personal details of approximately 50,000 individuals, predominantly French residents.

Cybersecurity officials issued urgent warnings about the risk of so-called "wrench attacks," where criminals use stolen information—including names, residential addresses, and cryptocurrency holdings—to physically intimidate victims or their families into transferring digital assets. French authorities confirmed such attacks have already taken place domestically and cautioned that Waltio users face elevated risk.

Officials also warned that attackers may impersonate security experts to deceive victims into voluntarily surrendering their cryptocurrency.

The incident occurs as France implements stricter oversight of digital asset businesses under the EU's Markets in Crypto-Assets Regulation (MiCA), which requires enhanced licensing and transparency standards. French regulators have mandated that non-compliant cryptocurrency firms either obtain proper authorization or cease operations by a June 30 deadline.