Bot communications are designed to look like normal (Web) traffic using accepted ports, so even firewalls and intrusion prevention systems have a hard time isolating bot messages.

• “一个僵尸（程序）真实地保存在机器中，维护一个命令和控制机制，以确保与僵尸主的通讯联系，并能在这个通讯中自我升级。