Hi, If for example your site is infected by malware and Google noted it at their search engine. You remove the malware but instead of sending a request for review at Google Webmaster tool you wait, will they automatically detect the fix (if yes how long) or continue to display the warning? Thanks
once you remove the malware, google webmaster tool will recognize the change within few days or whenever they do the next crawl. sometimes google recognize the change but takes a few extra days to update the webmaster tool status
I see thanks for the answer, if for example I was away for holiday and the warning stayed for more than a week, is it possible that Google will deindex my site?
I think it will take more than a week for Google to deindex your website if left untreated. I think the logic applies the same if say for example, your website is down for a couple of weeks due to hosting/server problems. Google would constantly check a website if it has been infected by malware, on the first instance, they will immediately label the website that it might be harmful for visitors and their computers to view. Google however, won't remove you straight away from the rankings unless a certain amount of time has passed. If the malware is left there for a couple of weeks or at less than a month then Google will start to consider temporarily removing you from the rankings up until the time the website has been fixed. Google would not want to show search results that would harm searchers. Once the website has been fixed (much better with the help of GWT as what sultanofseo has pointed out), Google will then review your website and if they see that everything is now A-ok, they will then put you back into rankings as time passes.
Yes, I agree with you, send resubmit immediately in Google Webmaster Tool and it will refresh by Google as soon as possible. All the best.