A global ransomware attack on Tuesday hit computers at Russia's biggest oil company, Ukraine's international airport, global shipping firm A.P Moller-Maersk and the world's biggest advertising agency WPP.
Following is a list of companies and organisations that have reported being hit by cyber attacks:
Russia's top oil producer Rosneft said its servers had been hit been a large-scale cyber attack but its oil production was unaffected.
Danish shipping giant A.P Moller-Maersk, which handles one out of seven containers shipped globally, said a cyber attack had caused outages at its computer systems across the world.
Maersk's port operator APM Terminals was also hit. Dutch broadcaster RTV Rijnmond reported that 17 shipping container terminals run by APM Terminals had been hacked, including two in Rotterdam and 15 in other parts of the world.
Britain's WPP, the world's biggest advertising company, said computer systems within several of its agencies had been hit by a suspected cyber attack.
Merck & Co
Pharmaceutical company Merck & Co said in a tweet its computer network was compromised as part of a global hack.
Russia's central bank said there had been "computer attacks" on Russian banks and that in isolated cases their IT systems had been infected.
All Russian branches of Home Credit consumer lender are closed because of a cyber attack, an employee of a Home Credit call centre in Russia said.
Ukrainian banks, Power Grid
A number of Ukrainian banks and companies, including the state power distributor, were hit by a cyber attack that disrupted some operations, the Ukrainian central bank said.
Ukrainian International Airport
Yevhen Dykhne, director of the capital's Boryspil Airport, said it had been hit. "In connection with the irregular situation, some flight delays are possible," Dykhne said in a post on Facebook.
French construction materials company Saint Gobain said it had been a victim of a cyber attack, and it had isolated its computer systems to protect data.
German postal and logistics company Deutsche Post said systems of its Express division in the Ukraine have in part been affected by a cyber attack.
Germany's Metro said its wholesale stores in the Ukraine had been hit by a cyber attack and the retailer was assessing the impact.
Food company Mondelez International said employees in different regions were experiencing technical problems but it was unclear whether this was due to a cyber attack.
The Netherlands-based shipping company said it was experiencing interference with some of its systems, following a global ransomware attack.
Russian steelmaker Evraz said its information systems had been hit by a cyber attack but its output was not affected.
A ransomware cyber attack is taking place in Norway and is affecting an unnamed international company, the Nordic country's national security authority.
A unit of candy manufacturer Mars Inc has been targeted by cyber attackers, and the company has isolated the issue, a spokeswoman for the company said.
India-based employees at Beiersdorf AG, the maker of Nivea skincare products, told Reuters the ransomware attack had impacted some of the company's systems in the country. The extent of the impact was unclear and Beiersdorf, which is based in Germany, could not be reached immediately for comment in India.
The Indian unit of British consumer goods company Reckitt Benckiser Group Plc, which owns brands such as Enfamil, Dettol and Lysol, was also hit by the ransomware attack, employees in India told Reuters. The extent of the impact on its systems was not immediately clear and the company could not be reached for comment in India....