This page shows up in Firefox and similiary in other web browsers when your website has been flagged as a Phishing or a Malware site. This means that your website has been compromised. What does it even mean "compromised"? Someone or some script created by somebody has modified files on your website with malicious code.
Once your website has been infected it can become inaccessible to visitors. When the Google, Yahoo, and Bing search engines detect that a site contains malware they flag it as being harmful in search results and block access to the it. The website may also be flagged and blocked by the Internet Explorer, Firefox ("Reported Attack Site!"), Safari, Chrome, and Opera web browsers. Most common problems are
Keep your search listings optimized by staying off search engine blacklists. Assure your customers that your site is malware free with the GeoTrust anti-malware seal.
Don't be a hacked site or webshop.
Get a low-cost daily anti-malware scan from GeoTrust that can identify both well-known malware and brand new malware strains. Clean up your site fast with instant alerts that clearly identify and locate malicious code. These alerts enable you to eliminate malware quickly, stay off search engine blacklists and keep search traffic flowing to your web site. Let your customers know that your site is malware free with an anti-malware seal from GeoTrust, the #1 most popular SSL brand on the web. This easy-to-implement cloud service is available directly from us.