French police arrest suspected hacker behind dozens of data breaches

French authorities have arrested a suspected hacker believed to be behind dozens of data breaches targeting public institutions, sports federations and private organizations across the country, prosecutors said Wednesday.

The suspect, a 20-year-old known online as HexDex, was detained Monday in western France and placed in police custody as part of an investigation led by the cybercrime unit of the Paris prosecutor’s office. Citing authorities, local media reported that the individual is linked to roughly 100 reports of website breaches filed since late 2025.

The suspect admitted to using the alias HexDex to claim responsibility for hacks and publish stolen data on cybercrime marketplaces such as BreachForum and Darkforum, prosecutors said. Authorities seized the suspect’s Darkforum account and computer equipment, which will now undergo forensic analysis.

French officials said the hacker allegedly targeted a wide range of organizations, including a handful of national sports federations — among them sailing, athletics, motorsports, gymnastics, skiing, rugby league, aikido, university sports, mountaineering and climbing, and para-sports.

Other victims included food banks, hotel chains Logis Hôtels France and Brit Hotel, as well as the Philharmonie de Paris concert hall.

Authorities also linked the suspect to a breach of the French Ministry of National Education’s “Compas” database, a human resources system used to manage trainee teachers in primary and secondary schools.

That mid-March cyberattack exposed personal information belonging to about 243,000 employees, most of them teachers. Compromised data included names, addresses, phone numbers and records of employees’ absences.

Investigators also believe the suspect breached a government weapons information system containing records of firearm owners, according to French media reports.

French authorities have been investigating several recent high-profile data breaches. In January, police arrested an 18-year-old suspected of leaking and reselling personal data belonging to more than one million members of the French Shooting Federation (FFT).

Separately, French officials said earlier this week that a cyberattack on the website of the National Agency for Secure Documents (ANTS) — the government portal used to manage identity documents and driver’s licenses — may have exposed users’ personal data.

Authorities have not indicated whether the suspect arrested this week is connected to those incidents. The investigation into the recent breaches remains ongoing.