They are part of the Messina branch of the "C3N", acronym for the Center for the Fight against Digital Crime, with eight gendarmes and which covers 18 departments in eastern France.

Pierre, a 29-year-old former mobile policeman, volunteered to join it a year ago.

He was directly plunged into the deep end by investigating the anti-vaccine group "V_V", accused of having harassed three people on the internet between spring and the end of summer 2021, including Moselle MP Isabelle Rauch (Horizons).

Eight people from this group were arrested last January across France.

The job requires adapting and "taking an interest in computer science", because the "techniques" used by criminals "evolve" constantly, says Pierre.

"Cyberdelinquency is constantly adapting", abounds its head, the boss of the research section (SR) of Metz, Colonel Denis Hebinger, who heads the cell.

Scams, phishing, ransomware, cyberbullying, downloading child pornography files, in addition to "classic crime that relies on cyber": between 2020 and 2021, online offenses increased by 30%, notes Mr. Hebinger.

Now "one in ten offenses is cyber", a figure "on the rise", he adds.

Racist insults against footballers

Among current scams, he and his colleagues note that "ransomware" is "exploding": "malicious program" enters a computer system, blocks data and computers, and cybercriminals demand a ransom in exchange for a decryption key, sometimes threatening to disclose the data, details Mr. Hebinger.

“Heavy attacks” which target businesses, hospitals, communities and individuals alike.

Among the forty investigations for which they are currently responsible, two target this type of software.

“We recommend not to pay”, insists Mr. Hebinger, specifying that it is “almost impossible to recover 100% of the data”.

Colonel Denis Hebinger (right) and Lieutenant Louis-Marie Lamballe (left) check hard drives at the Center for the Fight Against Digital Crimes, December 15, 2022 in Metz © JEAN-CHRISTOPHE VERHAEGEN / AFP

The scams in the sale of wood or heating pellets are the other novelty of the moment, underlines Lieutenant Louis-Marie Lamballe, 24, at the head of the cell.

With the seven other investigators, he flushes out fake investment sites in cryptocurrencies, diamonds, fine wines... "The imagination of crooks has no limit".

These days they are also keeping watch to track down any new racist insults on social networks against players from the French football team, some of whom were targeted online after the defeat in the World Cup final. against Argentina on Sunday.

And cybergendarmes can also exploit data from servers, computers, telephones or even car GPS to "search for digital evidence" during investigations.

Mia case

Thus in the case of the kidnapping of little Mia in the spring of 2021, they had searched some 120 seals - computers, tablets, USB keys ... - to "find communications useful to the investigation", such as "elements on the financing of operations," says Mr. Hebinger.

Sometimes these gendarmes take on false identities to track down drug traffickers or child criminals, a "framed" investigation technique, explains the head of the SR: investigators slip into the shoes of a teenager, for example, and give false appointments you in an attempt to arrest suspects.

An agent monitors his screens and tracks down cybercriminals at the Center for the Fight Against Digital Crimes, on December 15, 2022 in Metz © JEAN-CHRISTOPHE VERHAEGEN / AFP

Are they sometimes unmasked?

No, replies Lieutenant Lamballe, because opposite, "these are people ready to take action".

And in these investigations, the arrests are for him "always significant" because he has "the feeling of protecting minors".

New monitoring techniques also allow the gendarmes to "go back to individuals who download en masse" child pornography files, which include a particular encoding, identifiable as a signature, specifies Colonel Hebinger.

Thanks to this targeting, they were able to detect "more than 300,000 files present on computer media" and arrest four people in Meurthe-et-Moselle last September.

© 2022 AFP