Blog entry at
http://googleonlinesecurity.blogspot.com/2009/10/malware-warning-review-process.html

"As part of Cyber Security Awareness Month, Google's Anti-Malware Team is publishing a series of educational blog posts inspired by questions we've received from users. October is a great time to brush up on cyber security tips and ensure you're taking the necessary steps to protect your computer, website, and personal information.

Google's anti-malware efforts are designed to be helpful to both webmasters and website visitors.
...."

About the procedure can be read via blog entry.

And
http://googleonlinesecurity.blogspot.com/2009/10/show-me-malware.html

Google reveals anti-malware tool for webmasters:
http://www.itproportal.com/security/news/article/2009/10/14/google-reveals-anti-malware-tool-webmasters/