Malware or spyware is often confused as being something that can only come from opening a bad email attachment. In fact, there are many web pages that contain this kind of additional code, which can cause havoc for your personal computer or even a network you are in. In many cases, sites and pages use tracking software which some would also consider to be spyware or malware. However, in most of these cases there is little damage that the program could do, and it will in fact increase your user experience by customizing your pages to your past behavior.
So what kinds of malware could be bad? Google apparently uses a system that can help you find out. A recent thread at WebmasterWorld forums discusses the following introduction by a member:
While searching for a specific keywords or just typing my domain name in Google and after clicking on my site, it generates a warning named: "Malware Warning". Further they say: "Warning - visiting this web site may harm your computer! You can learn more about harmful web content and how to protect your computer at StopBadware.org."Although some interesting and valuable discussion follows, one of the best replies came in the form of a post from Google Engineer Matt Cutts, who describes a similar discussion occurring in the Webmaster Central Google Group. Matt explains that people that claim they are seeing this result for a site that does not have any malware should look more closely.
I’ve checked out a quite a few “we don’t have any malware” reports at this point, and I’ve yet to see a false positive.