As yet unidentifed hackers have managed to steal employee salary payments at several Swiss universities, officials said Sunday.

"According to our information, several top schools in Switzerland have been affected," Martina Weiss, director general of the rectors group of Switzerland's public universities, told AFP.

The hackers used information obtained by phishing -- tricking a person into passing on their personal details -- for their attacks on at least three universities, including the University of Basel.

According to the SonntagsZeitung newspaper, they accessed the universities' payment systems and changed the instructions on salary transfers, stealing a six-figure sum.

The University of Zurich managed to fend off the hackers after employees recognised their modus operandi.