1. A method comprising, at a computer system: rendering a document object model (DOM) object of a website using website information; generating, by a hardware processor of the computer system, a hash signature of the DOM object of the website by: applying a number of hashing functions to each of a plurality of data portions separated from content within the DOM object of the website; and generating a hash signature of the DOM object of the website by selecting a number of hashed data portions of the plurality of hashed data portions; obtaining a known hash signature of a DOM object associated with each of a plurality of known websites associated with a classification; comparing the hash signature of the DOM object of the website to a known hash signature of the DOM object associated with each of the plurality of known websites, wherein comparing the hash signature of the DOM object of the website to the known hash signature of the DOM object associated with each of the plurality of known websites includes comparing each of the plurality of hashed data portions to a plurality of known hashed data portions of the known hash signature; based on determining that the hash signature of the DOM object of the website does not match the known hash signature of the DOM object associated with each of the plurality of known websites: for each of the plurality of known websites associated with the classification: computing a similarity measurement between the hash signature of the DOM object of the website and the known hash signature of the DOM object associated with the known websites associated with the classification; determining whether a threshold associated with the classification is satisfied based on the similarity measurement computed between the hash signature of the DOM object of the website and the known hash signature of the DOM object for each of the plurality of known websites; and determining whether to classify the website as confirmed for the classification based on determining whether the threshold associated with the classification is satisfied.