1. A method, comprising: generating one or more graphs using data obtained from a query log, the one or more graphs including at least one of an anticlick graph or a view graph; ascertaining values of one or more syntactic features of the one or more graphs; determining values of one or more semantic features of the one or more graphs by propagating categories from a web directory among nodes in each of the one or more graphs; and detecting spam hosts based upon the values of the syntactic features and the semantic features.