Study on Covert Channel based on the DNS Protocol
Zhi Xue · Information Security and Communications Privacy · 2011
Covert channel can be employed to transfer information in a security-policy-breaking manner.Recently,covert channels in computer network protocols becomes a hot topic DNS protocol underlies the conversion of hostnames into IP address on the internet,and as a bidirectional protocol,is required by most computer networks,so it possible to establish,based on DNS protocol the covert channel.This paper first presents the concept of covert channel and DNS tunnel,the core of the DNS tunnel system,then describes the use demonstration of DNS tunnel tool,and finally proposes some improvements for more effective data transfer by DNS tunnel.