Cloudmark's service becomes aware of a new spam or phishing attack through reports from users like you, Each time a user clicks the Block Spam or Block Phishing button in the Cloudmark Desktop toolbar, Cloudmark evaluates this feedback based on the user's rating. When a sufficient number of high-rated users block the same spam or phishing attack, Cloudmark blocks it for all users throughout the network, usually within minutes of the origin of the attack.
Ratings are calculated by the Trust Evaluation System. A user who blocks the same messages that are blocked by other high-rated users will achieve a high rating, and Cloudmark gives greater weight to feedback from users with high ratings. A user who blocks newsletters or other legitimate messages, or who does not block spam and phishing messages blocked by the rest of the community, may be assigned a low rating. By giving less weight to the feedback of low-rated users, Cloudmark prevents spammers from tricking the system by unblocking their own spam messages.
Cloudmark uses a set of complex algorithms to identify the "fingerprints" of the spam and phishing messages that users block. These algorithms are sophisticated enough to identify spam and phishing even if spammers re-arrange their contents or hide them inside an image. A spam or phishing attack may mutate many times in order to thwart other anti-spam products—but Cloudmark identifies and blocks all permutations of any attack.
Last updated: 2008-09-03 17:58:11
Keywords: blacklist