Hackers have attacked servers containing sensitive information at the World Economic Forum, a spokeswoman for the Davos, Switzerland-based organization confirmed on Monday.

She was unable to give further details but according to a report in the Zurich-based newspaper, SonntagsZeitung, hackers were able to gather information, such as credit card information, about people who have attended the annual World Economic Forum event, including former U.S. President Bill Clinton, Palestinian leader Yasser Arafat, and Microsoft’s chairman and chief software architect Bill Gates.

Reporters from SonntagsZeitung were shown a CD-ROM with the stolen information from 27,000 of the world’s political and business leaders, the report said. The hackers were unnamed but are believed to be protesters against globalization.

The stolen information included telephone numbers, e-mail addresses, payment details, hotels and room numbers as well as flight arrival and departure times of individual participants, the report said.

The World Economic Forum, in Davos, Switzerland, can be contacted at http://www.weforum.org/.