May 12 (Reuters) - A global cyber attack on Friday affected British hospitals, government agencies and companies in 99 countries, with Russia, Ukraine and Taiwan the top targets, Security software maker Avast said.
Hacking tools widely believed by researchers to have been developed by the U.S. National Security Agency that were leaked online last month appear to have been leveraged to launch the attacks.
Around 1,000 computers at the Russian Interior Ministry were affected by the cyber attack, a spokeswoman for the ministry told Interfax.
Here are some of the companies affected:
* FedEx Corp
* Telefonica SA
* Portugal Telecom
* Telefonica Argentina
Compiled by Lisa Shumaker