A massive cyber-attack has affected Russian and Ukrainian companies and government agencies.
The virus known as Petya has affected Rosneft, Bashneft, Mars, Nivea and Mondelez, the International producer of Alpen Gold chocolate – all Russian companies.
Affected Ukrainian establishments are Auchan Hypermarkets, Privatbank and local telecommunication operators.
Ukrainian state power company and Kiev’s main airport, were among the first to report issues.
British advertising agency WPP also said some of its IT systems have been disrupted.
The Chernobyl nuclear power plant has also had to monitor radiation levels manually after its Windows-based sensors were shut down.
Experts suggest the malware is taking advantage of the same weaknesses used by the Wannacry attack last month.
“It initially appeared to be a variant of a piece of ransomware that emerged last year,” said computer scientist Prof Alan Woodward.
The Russian cybersecurity firm Kaspersky Lab reported that it believed the malware was a “new ransomware that has not been seen before” despite its resemblance to Petya.
Group-IB, a company which deals with prevention and investigation of cyber crime, said the virus operates like a ransomware as it blocks computers and requires a ransom of $300 in bitcoins.
Earlier, statements published on social networks said a computer virus had attacked the websites and computer systems of numerous Ukrainian companies, banks, state agencies and other institutions.
Ukraine’s national bank was the first to report a cyber-attack, warning banks and institutions about a dangerous malware.
According to the country’s media outlets, dozens of big banks, particularly Oschadbank and Privatbank, have limited customer service operations.
The Ukrenergo national energy company, as well as the Kievenergo, Zaporozhenergo and Dneprenergo energy supplying companies, have been facing difficulties, but their basic activities have not been affected.
Private delivery companies such as the Novaya Pochta have suspended its activities due to a computer virus.
Also, Antonov aircraft-builder, the Kiev metro and Borispol international airport have confirmed cyber-attacks on their computer systems.
A number of the Ukrainian media outlets have also reported cyber-attacks.
