Norton Safe Web
Norton Safe Web (sometimes abbreviated NSW) is a service developed by Symantec Corporation that is designed to help users identify malicious websites. Safe Web delivers information about websites based on automated analysis and user feedback.
In addition to actively crawling and analyzing web sites, Norton Safe Web relies on feedback from users and Norton Community participants. When a drive-by download occurs at a web site, the suspicious URL is automatically reported to Norton Safe Web for analysis. The reported site is rated as unsafe if the analysis confirms that the download is malicious.
To ensure that its site rating accurately reflects the current state of a site, Norton Safe Web performs frequent re-analysis of Web sites. Norton Safe Web employs a site rating aging algorithm which estimates how often the safety of a particular Web site will change. Some of the factors used in this analysis include the site's rating history, the site's reputation and associations, the number and types of threats detected on the site, the number of submissions received from Norton clients, and site traffic. In other words, unsafe sites that are more likely to have been cleaned up are re-analyzed often while those that might take longer to remove detected threats are re-analyzed less frequently. User reviews are also accepted, with contributors ranked by reputation. Should a site owner dispute the ranking of their site, they can submit a request for re-evaluation after completing a validation process.