A carmaker was the first major French corporation that admitted, on Saturday morning, it had been hit by the recent tsunami-sized WannaCry ransomware cyber attack that has affected networks in scores of countries around the world.

The WannaCry announced itself yesterday on computer screens worldwide with the following doom-laden message: "Oops, your files have been encrypted!" and accompanying instructions on how to recover the hacked files, once a ransom had been paid.

Ransomware is a malware program that encrypts the victim's computer files and unless a ransom is paid in, say, the virtual currency Bitcoin, their files will be erased or openly posted on the internet.

According to Renault's corporate management, quoted in French media, the carmaker was evaluating the current situation and since yesterday had taken remedial measures to fight the viral infection.

Renault added it had suffered similar attacks in the past but without such dramatic effect.

The French National Security agency for Information Technology (ANSSI) posted yesterday an attack alert warning of the presence in cyberspace of a stealthy program that inserted itself into computer networks and remotely exploited system vulnerabilities to propagate itself"

In its communique, the ANSSI pointed out the malware program encrypts all computers files (and any network it is linked to)

The agency also added some security tips: If somebody discovers their computer has been infected, the ANSSI recommended to immediately switch off the affected network terminals to try and hinder the infection from propagating and avoid the destruction of documents.

It also recommended alerting the head of IT security, save all important documents on an external drive and not pay the demanded ransom.

"Paying a ransom does not guarantee that files will be unencrypted and furthermore it can compromise the chosen mode of payment, such as a credit card.