Google has added a service that informs users if their computer is infected with malware.

If a user's PC is infected, a yellow window will appear on the Google search results page informing the user that their computer appears to be infected, and offering information on how to fix the problem.

According to Damian Menscher, security engineer at Google, unusual search traffic was found while performing routine maintenance on one of its data centres and research determined that the computers exhibiting this behaviour were infected.

He said: “This particular malware causes infected computers to send traffic to Google through a small number of intermediary servers called proxies. We hope that by taking steps to notify users whose traffic is coming through these proxies, we can help them update their anti-virus software and remove the infections.”

Talking to SC Magazine, Eddy Willems, security evangelist at G Data, said that he felt that this was a good thing, as it is another way to prevent malware spreading. "The other thing is that this can be manipulated by malware writers as this can be used to trick users into installing fake anti-virus and that is the only problem I have with it," he said.