A system and computer based method are provided for identifying active content in websites on a network. One embodiment includes a computer based method of classifying web content. The method receives content of a web page, and determines a first property associated with the content, the first property including static content. The method executes active content associated with the webpage, and determines a second property associated with the content based at least in part on the executing, the second property including the active content. The method also evaluates a logical expression relating the first property and the second property, and associates the web page with a category based on a result of the evaluation. The evaluation of the logical expression at least in part evaluates whether a constant value matches at least a portion of the content of the web page.