Factbox - Companies hit by global ransomware attack on June 27

The logo of Russia's oil producer Rosneft is seen on a board at the St. Petersburg International Economic Forum 2017 (SPIEF 2017) in St. Petersburg, Russia, June 1, 2017. Picture taken June 1, 2017. REUTERS/Sergei Karpukhin

(Reuters) - 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: