1. A computerized method for discovering and identifying advanced persistent threats (APT) using an APT detection center, comprising: receiving, by an APT server, an object to be classified; extracting features describing behavior of the received object; storing the received object along with the extracted features in an APT database; comparing the extracted features with features of objects in the APT database using an APT classifier; and flagging the received object as an APT object in the APT database in response to determining that the extracted features include one or more APT related features having a prescribed level of correlation with one or more features of known APT objects in the APT database.