French Tax Data Theft Using Stolen Staff Passwords Went Undetected for Seven Weeks
Sep 29, 2026
Data Breach / Network Security
An attacker used stolen passwords of staff at France's tax administration to take tax data on hundreds of thousands of taxpayers and businesses in June and July. Neither the tax administration nor France's national cybersecurity agency saw the data leave. The attack was not sophisticated, the agency, ANSSI, says in a report (in French) published on Tuesday: it worked because of weak login protection, poorly separated networks and gaps in monitoring. The tax administration, known as the DGFIP, runs France's tax website, impots.gouv.fr. The data came from E-Contact, the tool taxpayers use to message the tax administration. The stolen data covers a little over 350,000 individuals and a little over 250,000 businesses , the DGFIP says. Taxpayers' own online accounts and passwords were not compromised. For individuals, the data that may have been viewed or copied includes their tax ID, contact details, family situation, reference taxable income and tax...