9. An anti-spam tool executable by a processor, wherein the anti-spam tool is embodied on computer-readable memory and co-installed with a web browser on a computing device, and interfaces with the web browser through a program interface, the anti-spam tool comprising: a spam detection module determines whether a target webpage associated with a URL is spam; receiving at the web browser a URL of a webpaqe; determining by a spam detection module installed on the computing device whether the webpaqe is spam by comparing the URL of the webpaqe with a spam list including spam URLs, the spam list being created by: dividing the spam URLs of the spam list into a plurality of sub chunks of spam URLs; indexing the spam URLs into a first level index and a second level index, the first level index maps a first set of hash values to ranges of sub chunks of spam URLs, and the second level index maps a second set of hash values to the remaining sub chunks of spam URLs in the plurality of sub chunks; the first set of hash values are created using a first hash function and the second set of hash values are created using a second hash function; and performing an anti-spam action on the computing device if the webpage is determined to be spam; wherein comparing the URL of the webpage with the spam comprises: computing a hash value for the URL of the webpage using a hash function; and matching the hash value of the webpage with the set of hash values of the spam URLs; wherein the spam list is further created by: computing the first set of hash values and the second set of hash values; sorting the spam URLs by their computed hash values; wherein each sub chunk having a sequential range of hash values defined by a lower bound and an upper bound; a spam list indexer comprising an index of a spam list, the index including a plurality of groups that each include a plurality of spam URLs, wherein at least one group is assigned a hash value; and an anti-spam controller assist performs an anti-spam action if the target webpage is determined to be a spam.
9. An anti-spam tool executable by a processor, wherein the anti-spam tool is embodied on computer-readable memory and co-installed with a web browser on a computing device, and interfaces with the web browser through a program interface, the anti-spam tool comprising: a spam detection module determines whether a target webpage associated with a URL is spam; receiving at the web browser a URL of a webpaqe; determining by a spam detection module installed on the computing device whether the webpaqe is spam by comparing the URL of the webpaqe with a spam list including spam URLs, the spam list being created by: dividing the spam URLs of the spam list into a plurality of sub chunks of spam URLs; indexing the spam URLs into a first level index and a second level index, the first level index maps a first set of hash values to ranges of sub chunks of spam URLs, and the second level index maps a second set of hash values to the remaining sub chunks of spam URLs in the plurality of sub chunks; the first set of hash values are created using a first hash function and the second set of hash values are created using a second hash function; and performing an anti-spam action on the computing device if the webpage is determined to be spam; wherein comparing the URL of the webpage with the spam comprises: computing a hash value for the URL of the webpage using a hash function; and matching the hash value of the webpage with the set of hash values of the spam URLs; wherein the spam list is further created by: computing the first set of hash values and the second set of hash values; sorting the spam URLs by their computed hash values; wherein each sub chunk having a sequential range of hash values defined by a lower bound and an upper bound; a spam list indexer comprising an index of a spam list, the index including a plurality of groups that each include a plurality of spam URLs, wherein at least one group is assigned a hash value; and an anti-spam controller assist performs an anti-spam action if the target webpage is determined to be a spam. 12. The anti-spam tool as recited in claim 9 , wherein the anti-spam action comprises one or more of the following actions: blocking the webpage, displaying a warning against opening the webpage, highlighting a link to the webpage, and removing any links to the webpage from a parent webpage that is being opened by the web browser.