Google has a new form you can use to report false positives around security issues with your site. In short, if you think your site was mistakenly flagged by Google Search for security issues, you can ask Google for a review using the "Report a Security Issue" button.
I should note that this form is currently available in the English help docs right now and is a test. It may launch to a wider user base in the future. Google said it also "may expand the reporting system to cover other issues in the future, if this pilot is successful."
Google announced this on Twitter saying "we’re piloting a new reporting system beginning with security issues." "We're also providing a "Report a Security Issue" button to these pages, for site owners to report potential false positives or to request a re-review," Google wrote:
This button should be over here and looks like this:
So if your site gets booted from Google Search because of a malware, hack or other security issue, you can use this method to try to expedite re-inclusion.
Forum discussion at Twitter.