This chapter discusses how information hiding and steganography techniques can be used to make botnets stealthier and more dangerous. It focuses on techniques that can be used within a single node to implement a local covert channel allowing the attacker to exfiltrate data or to assimilate the device into the botnet. The chapter deals with state-of-the-art techniques and novel approaches to make command and control channels stealthier, for instance, by optimizing the network traffic or exploiting novel Internet of Things standards. It provides a review of archetypal frameworks merging steganographic methodologies and botnets as well as a brief discussion of novel and cutting-edge detection techniques. The chapter presents the analysis of the most important covert channels to empower future botnets both in terms of ability of bypassing sandboxes and covertly exfiltrating data. It provides the introduction of novel detection schemes and network architectures to mitigate the impact of botnets.