Google has updated its search results page to also start informing users if their computer has a malware infection. The new service turns out to be a side effect of the search company detecting some unusual activity while performing maintenance at one of its data centers.The activity sparked an investigation with the collaboration of the companies sending the data to the data center in question. It turns out the activity was due to user’s machines being infected with malware meaning Google could detect individual machines that carried this infection just by flagging the activity patterns.The detection is possible because the malware being used accesses Google through a set number of proxy servers. So when Google notices traffic through one of these proxies it knows the machine sending the request is infected with this strain of malware.Rather than end the investigation there, Google decided to do something about the infected machines. So if you do a search and see the following message at the top of the results, it means you have a computer in need of an antivirus scan and malware removal.Google also offers a link that helps you to fix the problem by recommending what to search for to find an appropriate antivirus solution. Google also hosts a page with its own security software recommendations.via The Official Google BlogMatthew’s OpinionIt’s all well and good running an antivirus or complete security suite on a PC, but if a machine is already infected the chances are the user has no idea. Malware writers are very careful to make their malicious software as silent as possible. They want the program(s) to work in the background without a user’s knowledge.There is a gray area regarding whether companies should have the right to detect an infected machine and contact the owner of that PC. I am certainly on the side of contacting the owner as it’s in their interests to do so. This move by Google is a positive one as it is unintrusive while telling the user their machine has been compromised. It’s also likely to be very effective as search, and in particular Google Search, is so popular.