The software scans and classifies web addresses to provide the user with safety rating of URLs before the user visits them. Proactively alerting the user of potentially malicious web addresses in links of search results, and ads and other selected web pages. The software protects the user from webpages that could be used to compromise the user's privacy and identity. Unlike other products on the market that are based on static databases containing information on web domain reputations, the software scans each URL as it currently exists on the web, each time the address is displayed in the user's browser. This code analysis approach is a more efficient method than most alternatives for detecting malicious behavior.