Google Warns Searchers Of Windows Malware Infection

Hundreds of thousands of people using Google Search have seen this message atop a search results page recently: "Your computer appears to be infected." While finding malware on one's computer can be disconcerting, it's also disconcerting to consider that Google appears to know what's on your computer. In fact, Google doesn't know about your applications, apart from those you use to access Google services on the Internet. If the company has identified malware on your computer, it's because your computer is probably infected with malware that hijacks Google search results and redirects search traffic to websites for payment.

For years, Google has presented alerts about websites in its search index that it believes may have been compromised to serve malware. It has also provided open-source Web security research tools such as skipfish, ratproxy, and DOM Snitch. This is the first time Google has applied its knowledge of Internet network traffic to identify malware on its users' local computers.

Google security engineer Damian Menscher said the company's security team discovered unusual search traffic while performing routine maintenance on one of its data centers. "After collaborating with security engineers at several companies that were sending this modified traffic, we determined that the computers exhibiting this behavior were infected with a particular strain of malicious software, or 'malware,'" he explained in a blog post. 

The malware prompts infected Windows computers to send traffic to Google through proxy servers. Google is detecting traffic that comes from these servers and notifying users sending the traffic that their computers appear to be infected.
Google says that that several million PCs appear to be affected, that it has warned several hundred thousand people, and that the source of the infection appears to be one of roughly a hundred variants of fake antivirus software. The company says it is not aware of a specific name for the fake antivirus software responsible for the infection.
Google advises that users utilize current antivirus software to scan for an infection and to be wary of inadvertently installing fake antivirus software in an attempt to correct the problem. If legitimate antivirus software fails to fix the issue and Google searches still bring a warning message, Google provides instructions for manually cleaning one's Windows hosts file, through which the malware redirects Web requests. 

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