The paper's own research found that the details were accurate.
The hackers approached a Swiss newspaper, Sonntagszeitung, with data including mobile phone numbers, credit card numbers and home addresses of such figures as Bill Gates of Microsoft and Palestinian leader Yasser Arafat.
The paper's own research found that the details were accurate.
The WEF confirmed that its computer security had apparently been breached during its annual gathering, which ended on 30 January, and that it was treating the matter as a crime.
"We do take this very seriously, and we are going to be investigating this aggressively", WEF communications director Charles McLean told Reuters news agency.
Possible anti-globalisation link
He refused to speculate as to whether the hackers might be anti-globalisation protesters.
Activists targeted the forum - which brings together over 1,000 leading business and political figures each year - but were mostly kept out of the Swiss resort town by a heavy police presence.
They staged a counter-event, the World Social Forum, in Brazil during the Davos meeting.
Mr McLean said the hackers might have broken into the computers at the forum's registration centre in Davos.
But it is not clear exactly what list the hackers have. At least one report said that Bill Clinton was on the hackers' list, but he was not at Davos this year.
Digital divide
Ironically, one of the themes of this year's Davos forum was bridging the digital divide, as global leaders warned that the lack of computers and internet access in many developing countries was increasing economic inequality.
UN Secretary General Kofi Annan pointed out that many of the world's poor do not have electricity or telephone lines, much less computer access.
The counter-summit in Brazil, however, showed that its organisers were web-wise - part of it was webcast live on the internet.