Cyber attack hits Europe, 'unprecedented' says Ukraine Prime Minister

Hackers have caused widespread disruption for businesses, banks and airports across Europe in an infection reminiscent of last month's WannaCry attack.

The virus is sweeping Russia, England and India, but Ukraine seems to have been hit hardest with its Central Bank, local transport and Kiev's Boryspil Airport all affected.

The source of the attacks was not immediately clear.

However a researcher for Kaspersky Lab identified the virus as Petrwrap, a strain of the Petya ransomware identified by the firm in March. One recovered sample was compiled on June 18, suggesting the virus has been infecting machines for some time.

A computer screen cyberattack warning notice reportedly holding computer files to ransom, as part of a massive international cyberattack, at an office in Kiev, Ukraine. Photo / AP

British advertising giant WPP and the French industrial group Saint-Gobain said they came under attack and put protection protocols in place to avoid data loss.

Robin Dargue, WPP's group chief information officer, has notified agencies that a number of companies within the group have been hit with a ransomware virus.

Danish shipping company Maersk said systems were down across multiple sites, while the virus also reached servers for the Russian oil company Rosnoft.

The British National Cyber Security Centre said it was "aware of the global ransomware incident" and is "monitoring the situation closely".

"There have been indications of late that Petya is in circulation again, exploiting the SMB (Server Message Block) vulnerability," the Swiss Reporting and Analysis Centre for Information Assurance (MELANI) said in an email.

Ukraine's prime minister says that a cyberattack affecting his country is "unprecedented," but "vital systems haven't been affected."

Prime Minister Volodymyr Groysman also said on Facebook that "our IT experts are doing their job and protecting critical infrastructure ... The attack will be repelled and the perpetrators will be tracked down."

Ukrainian Deputy Prime Minister Pavlo Rozenko on Tuesday posted a picture of a darkened computer screen to Twitter, saying that the computer system at the government's headquarters has been shut down.

There's very little information about who might be behind the disruption, but technology experts who examined screenshots circulating on social media said it bears the hallmarks of ransomware, the name given to programs that hold data hostage by scrambling it until a payment is made.

The scale and use of ransomware has similarities to last month's cyber attack, which some experts linked to North Korea.

This hit dozens of countries and used a flaw that was once incorporated inside the National Security Agency's surveillance tool kit.

The world is still recovering from last month's WannaCry or WannaCrypt virus, which brought the UK'S NHS to its knees.