COMPUTER experts are warning fleets to be on their guard against software that is downloaded by internet users without their knowledge and tracks their use of the web.

Spyware is beginning to prove a bigger threat than traditional viruses to fleet computer systems, they claim.

It typically downloads in the background while an internet site is visited and runs continuously, monitoring use for targeted advertising.

For example, if a website with the word ‘car’ in its address was visited, the spyware would pop up a window advertising a particular car sales web site, the experts say. The warning comes from fleet software company cfc, based on analysis of problems recorded and resolved by its helpdesk during 2004.

It said it was the first year the IT industry as a whole reported spyware causing more call-outs to computer technicians than viruses.