Spyware infiltrates the ad industry

Spyware writers are generating $2bn (£1bn) of revenue annually after capturing 25 per cent of the online advertising market, an anti-spyware vendor claimed this week.

Research from Webroot found that spyware - programs that are secretly installed on a user's PC and cause advertising pop-ups and homepage hijacking - was found on 88 per cent of consumer computers and 87 per cent of business computers scanned by Webroot between January and April of this year.

Richard Stiennon, Webroot’s vice-president of threat research, said: "Our research shows that some form of spyware, adware or potentially unwanted software can be found on 87 per cent of corporate PCs. This figure is disconcerting from a security perspective and also from an IT support perspective, as spyware can often slow down the performance of an entire network."

However, security experts have questioned the validity of the research as Webroot defines 'spyware' as both unwanted programs and cookies. Cookies are files used by legitimate websites to gather information about a user's activity on that site and are present on most computers that run a web browser. Many argue that cookies are not dangerous.

Clive Longbottom, an analyst at Quocirca, said: "A cookie on its own won't do it, but combined with spyware it is [dangerous]. This is an area where you have to be careful as the financial institutions, for example, use cookies. But we would advise companies to cleanse desktops, whether they use free or supported tools to do so."

Longbottom also doubted that spyware was generating $2bn a year.

"For companies trying to get marketing through backdoors, I can't see that there's $2bn available for this," he said. "It seems a hell of a lot of money to me."

Webroot said it took its research from online audits. It found that a program called 'CoolWebSearch', which avoids detection by many anti-spyware tools, was the most widespread "threat" it found.

Dan Ilett writes for ZDNet UK