New Trojan Horse Communication Model Based on WebMail System

Communication technologies of Trojan horses are studied, and a communication model using WebMail system as a broker is proposed. With the model, the controlled end of the Trojan horse accesses WebMail systems in Internet by HTTP and can easily pass through the firewall of LAN. The controller does not need public or fixed IP addresses, so it can work well in places like cybercafe. To validate the model and evaluate its hazard, a prototype Trojan horse is designed. Some advices on protection against this kind of Trogan horse.