Investigators are treating the explosion as a terror attack but did not immediately say who was to blame. Ukraine's National Bank was among the first to report a problem.
Rob Wainwright, executive director at Europol, said the agency is "urgently responding" to reports of the new cyber attack.
It included code known as "Eternal Blue", which cyber security experts widely believe was stolen from the U.S. National Security Agency and was also used in last month's ransomware attack, named "WannaCry."Victims could have protected themselves from attack by updating computers with security patches from Microsoft and configuring their networks to stop viruses targeting a widely used Windows networking protocol, said Symantec Corp (SYMC.O) researcher Eric Chien".
Banks were experiencing "difficulty in servicing customers and performing banking operations" due to the attacks, the bank said in a statement.
"To protect our data we have isolated our systems", Saint-Gobain told AFP. In addition, the Antonov aircraft-builder, the Kiev metro and Borispol worldwide airport have confirmed cyber attacks on their computer systems.More news: Bob Iger Evades Question About Han Solo Film Being Delayed
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Kyivenergo, a Ukrainian utility, switched off all computers after the hack, while another power company, Ukrenergo, was also affected, though "not seriously", the Interfax news service reported.
The cryptolocker demands $300 in bitcoins and does not name the encrypting program, which makes finding a solution hard, Group IB spokesman Evgeny Gukov said. It spread to other computers on companies' networks by leveraging software holes.
The strikes follow the global ransomware assault involving the WannaCry virus that affected hundreds of thousands of computers in more than 150 countries as extortionists demanded $300 in bitcoin from victims.
"The official airport website and the flight schedule are not working!" wrote airport director Pavlo Ryabykin on Facebook, though without confirming the website was hit by a virus.
Ukraine's delivery service company Nova Poshta confirmed the virus that hit its computers was Petya.A. "We are now asserting the situation", the company said.
Ransomware hit at least six countries Tuesday, including Ukraine, where it was blamed for a large and coordinated attack on key parts of Ukraine's infrastructure, from government agencies and electric grids to stores and banks.