"In a new report authored by Google Security Team member Niels Provos, who is also a senior staff software engineer in the company’s Infrastructure group, the search provider offers up some of its badware site trends analysis from the last 12 months, with the sheer volume of malware sites tracking ever upwards.
In June of 2008, Google was filtering roughly 150,000 badware sites per month. However, in August 2009, that number will approach 350,000, Provos said in a post to the company’s security blog. The reported numbers are derived from the Google Safe Browsing Malware List, which is fed by a free API that it distributes to webmasters to poll the MD5 hashes of known malware and phishing sites.
Users of Google’s search tools and Chrome browser, along with users of Mozilla Firefox and Apple Safari receive warnings when visiting sites that have been previously identified as dangerous by the API, and it is also used as part of the company’s efforts with Stopbadware.org." – Content courtesy of Online malware – Google: Malware Sites on the Upswing – eWeek Security Watch