Methods, systems, and computer-readable mediums containing programmed instructions are disclosed for detecting an intrusion in a communications network. Data packets processed by a transport layer of a network protocol associated with the communications network are scanned using signatures from a repository of the signatures. A determination is made if the scanned data packets are malicious. One or more actions are taken if any data packets are determined to be malicious. Methods, systems, and computer-readable mediums containing programmed instructions are also disclosed for preventing an intrusion in a communications network.