France's tax authority confirmed on August 14 that a cyber intrusion in late June compromised the personal and fiscal data of 678,000 taxpayers. Investigators say the breach was detected at the time but never publicly disclosed until a hacker using the alias ZeroBytes claimed responsibility on a criminal forum.
The Directorate General of Public Finances (DGFiP) said the unauthorized access followed an identity theft that granted entry to an internal VPN used by tax agents. From there, the attacker reached internal search tools for both individual and professional taxpayer records. DGFiP director general Amélie Verdier described the extraction method as "sophisticated": small-volume queries spaced with pauses, which evaded the automated alerts that typically flag bulk scraping.
The stolen dataset includes names, dates of birth, addresses, reference tax income, household composition, and withholding tax rates for 392,867 individuals and 285,570 professionals, according to figures cited by the monitoring platform FrenchBreaches from the hacker's own claims. Passwords and banking credentials were not taken. Among the individuals, 26,805 reported a reference tax income of €100,000 or more, 386 exceeded €1 million, and eight exceeded €10 million.