Google’s Anti-Malware Team has made available some of their research data on malware distribution mechanisms while the research paper is under peer review.
Among their conclusions are that the majority of malware distribution sites are hosted in China, and that 1.3% of Google searches return at least one link to a malicious site. The lead author, Niels Provos, wrote, ‘It has been over a year and a half since we started to identify web pages that infect vulnerable hosts via drive-by downloads, i.e. web pages that attempt to exploit their visitors by installing and running malware automatically.
During that time we have investigated billions of URLs and found more than three million unique URLs on over 180,000 web sites automatically installing malware. During the course of our research, we have investigated not only the prevalence of drive-by downloads but also how users are being exposed to malware and how it is being distributed.’