Cross-Site Malware Warning

Updated: September 15, 2009

It is possible for the Chrome, Safari, and Firefox (starting with version 3.5) web browser to identify a page on your website as containing malware and block it even if Google has not flagged your website as containing malware. This is due to the cross-site malware check that the web browsers perform. In addition to checking whether your website is being flagged, they check whether other websites whose content is included in your page is being flagged. When a cross-site warning is displayed it will indicate that your website "contains elements from the site" that is being flagged by Google. The types of content that can trigger a cross-site malware warning include JavaScript, iframes, frames, and Flash. In many cases the cross-site warning is indication that your website has been infected with malware. In these cases Google will begin to flag your website once it detects the malware on your site. In other cases the cross-site warning may be due to other websites whose content you include on your page, the content that is being included on your website may or may not actually contain malware in this situation.