McAfee SiteAdvisor plugin is an Internet service that helps to protect your computer from all kinds of web-based security threats including spyware, spam, adware, viruses, browser exploits, phishing, online fraud and identity theft. The service has automated testers that continually patrol the web to browse sites, download files, and sign-up for things with e-mail addresses so that it can test different sites. The plugin is available for Internet Explorer and Firefox and displays a color rating for each site visited. Learn more about McAfee SiteAdvisor or install it for Firefox with the directions on this page.