PARIS (Reuters) - Several French news companies, including Le Monde and Le Figaro, said their websites went temporarily offline on Wednesday because a company that helps speed delivery of their content was hit by a cyber attack.

The company, Cedexis, said it had come under a “unique and sophisticated” distributed denial of service attack, which is when hijacked and virus-infected computers target networks with data requests until they can no longer cope.

Magazine L’Obs, which was also affected, said the attack had also hit the websites of several big French manufacturers.

“This attack caused a partial but widespread outage that affected many of our customers,” Cedexis Chief Executive Ryan Windham said in a statement to Reuters.

The company said service had since come back and that it was conducting an investigation.

Internet security has become a top concern in France following the leak of hacked data from President-elect Emmanuel Macron’s campaign two days before the presidential election.