Other businesses affected by the attack include Danish conglomerate Maersk, Russian oil company Rosneft, Dutch shipping company APM Terminals, British advertising agency WPP and others.
Last month, CCN reported that a global ransomware campaign hit over 100 countries and netted attackers a few thousand dollars after infecting well over 100,000 computers.
More than 80 companies in Russian Federation and Ukraine were initially affected by the Petya virus that disabled computers Tuesday and told users to pay $300 in cryptocurrency to unlock them, according to the Moscow-based cybersecurity company Group-IB.
Security experts said they expected the impact to be smaller than WannaCry since many computers had been patched with Windows updates in the wake of WannaCry last month to protect them against attacks using Eternal Blue code.
Signs that this is a new strain led Kaspersky Lab malware analyst Vyacheslav Zakorzhevsky to say the outbreak comes from a "new ransomware we haven't seen before".
Security firms scrambled to understand the scope and impact of the attacks, seeking to confirm suspicions hackers had leveraged the same type of hacking tool exploited by WannaCry, and to identify ways to stop the onslaught.
The fight against cyberattacks has sparked exponential growth in global protection spending, with the cyber security market estimated at $120 billion this year, more than 30 times its size just over a decade ago. "We are taking steps to remedy the issue as quickly as possible", the firm said in a statement.
"As a result of these cyber attacks these banks are having difficulties with client services and carrying out banking operations", the central bank said in a statement.
Ukrainian companies and government agencies seem to have been hit particularly hard.
Ukraine's delivery service company Nova Poshta confirmed the virus that hit its computers was Petya.A. The country's National Bank was among the first to report a problem.
Ukraine's vice prime minister, Pavlo Rozenko, tweeted a screenshot of his malfunctioning computer saying computers at the Cabinet of Ministers have been affected. There are also reports that some businesses in the USA have also been hit by the attack, such as the American offices of law firm DLA Piper.
The technological systems were working "as usual" at the plant that exploded in 1986, however.
The automatic radiation monitoring system at the Chernobyl nuclear power plant was hit by a cyberattack Tuesday and monitoring was being carried out manually, according to a Ukrainian federal agency.
Ransomware victims are always advised not to pay the ransom to get their files back, and in this case, it would be futile. More than 30 victims paid into the bitcoin account associated with the attack, according to a public ledger of transactions listed on blockchain.info.