Buried deep beneath your feet lie the cables that keep the internet online. Crossing cities, countrysides, and seas, the internet backbone carries all the data needed to keep economies running and your Instagram feed scrolling. Unless, of course, someone chops the wires in half. On April 27, an unknown individual or group deliberately cut crucial long-distance internet cables across multiple sites near Paris, plunging thousands of people into a connectivity blackout. The vandalism was one of the most significant internet infrastructure attacks in France’s history and highlights the vulnerability of key communications technologies. Now, months after the attacks took place, French internet companies and telecom experts familiar with the incidents say the damage was more wide-ranging than initially reported and extra security measures are needed to prevent future attacks. In total, around 10 internet and infrastructure companies — from ISPs to cable owners — were impacted by the attacks, telecom insiders say. The assault against the internet started during the early hours of April 27. “The people knew what they were doing,” says Michel Combot, the managing director of the French Telecoms Federation, which is made up of more than a dozen internet companies. In the space of around two hours, cables were surgically cut and damaged in three locations around the French capital city — to the north, south, and east — including near Disneyland Paris.
“Those were what we call backbone cables that were mostly connecting network service from Paris to other locations in France, in three directions,” Combot says. “That impacted the connectivity in several parts of France.” As a result, internet connections dropped out for some people. Others experienced slower connections, including on mobile networks, as internet traffic was rerouted around the severed cables. All three incidents are believed to have happened at roughly the same time and were conducted in similar ways — distinguishing them from other attacks against telecom towers and internet infrastructure. “The cables are cut in such a way as to cause a lot of damage and therefore take a huge time to repair, also generating a significant media impact,” says Nicolas Guillaume, the CEO of telecom firm Nasca Group, which owns business ISP Netalis, one of the providers directly impacted by the attacks. “It is the work of professionals,” Guillaume says, adding that his company launched a criminal complaint with Paris law enforcement officials following the incident. Two things stand out: how the cables were severed and how the attacks happened in parallel. Photos posted online by French internet company Free 1337 immediately after the attacks show that a ground-level duct, which houses cables under the surface, was opened and the cables cut. Each cable, which can be around an inch in diameter, appears to have straight cuts across it, suggesting the attackers used a circular saw or other type of power tool. Many of the cables have been cut in two places and appear to have a section missing. If they had been cut in one place they could potentially have been reconnected, but the multiple cuts made them harder to repair.