Cyberattacks Spread From Ukraine to Europe, US

What Ukraine's prime minister calls an 'unprecedented' cyberattack in his country has begun to spread beyond Ukraine's borders.

"The attack is unprecedented but our IT experts are working on it and defending critical infrastructure," said Volodymyr Groysman, speaking of efforts to contain the crisis.

Banks, government offices and airports in Ukraine were among the first to report the cyberattack. Ukrainian Deputy Prime Minister Pavlo Rozenko Tuesday tweeted a photo of his black computer screen with a warning message, adding in a separate tweet that government offices have been paralyzed.

Ukrainian authorities have said the hacks could have been perpetrated by Russia, the Reuters news agency reported; however, Russian oil company Rosneft also reported having been hacked in all branches, both domestically and abroad.

The U.S. Department of Homeland Security said it is monitoring the attacks and is in contact with international and domestic partners.

'We stand ready to support any requests for assistance,' officials said in a statement.

Among those attacked was pharmaceutical company Merck.

'We confirm our company's computer network was compromised today as part of global hack. Other organizations have also been affected,' Merck said Tuesday on Twitter.

A number of other European companies reported being targeted as well, including British advertising giant WPP and French industrial group Saint-Gobain.

IT experts have identified the virus as a type of ransomware - a program that is often used to hold data 'hostage' until a payment is delivered.