Researchers told ABC News that they do not believe that a nation was behind the attack and suggested that it could have been launched by a lone cybercriminal. This likely has a lot to do with how much was priced in last month following the WannaCry ransomware breakout, as well as how easy it is to secure systems against the particular exploit that both attacks rely on.
Operations at the Kiev airport were paralyzed by the hack.
After the Wannacry attack, organisations around the globe were advised to beef up IT security. The central bank said an "unknown virus" was to blame for the latest attacks but did not give further details or say which banks and firms had been affected.
In the United States, Merck was hit, as was NY law firm of DLA Piper.
We confirm our company's computer network was compromised today as part of global hack.
While information is still being gathered about the attack itself-security researchers have been racing to examine strains of the attack to learn more about it.
Via Twitter, the company has informed users it "switched to a reserve control system", presumably stopping its services from being affected.
The nuclear power plant was the site of the world's worst nuclear disaster in 1986 when a reactor exploded. DLA Piper, an worldwide law firm, reported phone systems down in offices in the United Kingdom, elsewhere in Europe, the Middle East and the U.S.
"Images from other affected computers and disabled cash points showed what appeared to be ransomware, demanding a payment of $300 (£235) in Bitcoin to re-gain access to encrypted files", according to The Independent article.
The cryptolocker demands $300 in bitcoins and does not name the encrypting program, which makes finding a solution hard, said Group IB spokesman Evgeny Gukov in an emailed comment.
Danish shipping giant A.P. Moller-Maersk said it was among the victims, reporting outages at facilities including its Los Angeles terminal.
Ukrainian Deputy Prime Minister Pavlo Rozenko said the government's computer network went down and the central bank reported disruption to operations at banks and firms including the state power distributor.
Rob Wainwright, executive director at Europol, said the agency is "urgently responding" to reports of the new cyber attack.
Maersk reported its IT systems were affected by the attack, with local media showing the same ransom message from the firm's offices in Rotterdam, Reuters reported.
WPP, a British advertising agency, and Sain-Gobain, a French construction materials company, are just two examples of other large companies targeted across Europe, reports The New York Times. Rosneft, a massive Russian energy company, said it had been impacted, as well.