Malware review tips
I want to stress a few facts about the review process.
Do request the review. It was noticed that it takes significantly longer to remove the warning if the malware scanners find you site clean without a review request from a site owner. When they know that the site owner is aware of the problem, the process becomes smoother and the warning can be removed in just a few hours after a successful review.
Request the review as soon as possible. Although Google’s malware scanner can automatically visit your site, they are not as ubiquitous as Googlebot and it may take weeks before the next scheduled visit.
Don’t be afraid to request the review even if you are not sure that your site is completely clean. If any security issues are detected during the review, they will be reported in your Webmaster Tools account. Then you can fix them and request another review.
Don’t delete infected web pages. If Google reports specific URL as examples of web pages where malicious content was found, it expects to find these pages clean during the review. If the pages cannot be found, it may be considered as if they were temporarily removed just to pass the review. If you don’t need specific pages, try to empty them (you can remove them after a successful review) or configure your web server to return the 410 Gone error. (This information is not from official Google’s sources. It’s based on my own observations)