French authorities have launched a preliminary investigation into a data breach involving Waltio, a cryptocurrency tax reporting platform, amid concerns that users’ personal information may have been compromised.
In a notice issued Thursday, French cybersecurity authorities said the Paris Public Prosecutor’s Office and the National Cyber Unit are examining what data was stolen and which Waltio users may have been affected. Officials warned that exposed users could be targeted by criminals posing as security professionals in an attempt to steal their digital assets.
The warning follows a report by French newspaper Le Parisien, which said a hacker group known as Shiny Hunters claimed responsibility for the attack and issued a ransom demand to Waltio. The hackers reportedly accessed personal data belonging to around 50,000 users, most of whom are based in France.
Authorities cautioned that leaked information such as names, addresses, and details related to crypto holdings could put users at serious risk. Criminals have increasingly targeted crypto holders after obtaining personal data, sometimes approaching victims directly or contacting family members to pressure them into transferring digital assets.
This type of crime is often referred to as a “wrench attack,” where attackers use threats or physical coercion to force victims to hand over their cryptocurrency. French authorities said such incidents have already occurred in the country and warned that similar risks exist for affected Waltio users and their relatives.
The investigation comes as France tightens oversight of the crypto sector during the European Union’s transition to the Markets in Crypto-Assets Regulation (MiCA) framework. Under MiCA, crypto companies operating in the EU must comply with new licensing and transparency requirements.
French financial regulators have reportedly warned crypto firms that are not compliant with MiCA rules to either apply for authorization or shut down their operations in the country. The transition period for compliance is set to end on June 30.


