Google has a feature that will mark websites as harmful if it contains malicious code, or code deemed to be harmful for potential visitors.
If Google marks your website as having malware, or malicious code on your pages, you can request that Google re-evaluate its stance on your website by following these steps:
- Remove all malicious code on the website
- Perform upgrades to any scripts you are using
- Go to the Google Diagnostics page to confirm compliance:
Replace the above-mentioned items that are in BOLD with your website
- Login to Google Webmaster Tools (Create account if you do not already have one)
- Click on the "Overview" page and then click "Request Review"
Upon completing the application Google can take up to ten working days to process the request and give their verdict.