The number of companies reporting a spyware infestation has increased by almost half in the past 12 months, according to a new survey. In addition, 17 percent of companies with more than 100 employees have spyware such as a keylogger on their networks, said the authors of the annual Websense Web@Work survey, published on Tuesday. "This is almost 50 percent growth in the instances of keyloggers that organizations are reporting back," said Joel Camissar, a manager for Internet security specialist Websense.

"Despite the organizations' having a 'best of breed' antivirus, anti-spyware and firewall, we are still detecting a huge amount of back-channel spyware communication." Spyware is seen as an increasingly serious security problem, and the U.S. Federal Trade Commission has pledged to take action against companies that distribute it. The software is installed on machines without the owner's knowledge to track their online habits, sometimes via a keylogger, which records the user's keystrokes.