Networks of large numbers of compromised devices are assembled by evildoers to spread malware and orchestrate a range of attacks, including spam and DDoS. Along with the rise of a significant number of IoT botnet families, like Mirai and Hajime, alerting is the fact that botnets are increasingly used for spreading malware of a versatile nature. According to a recent report by Kaspersky Lab pertaining to the first half of 2018, multifunctional bots, and particularly remote access tools (RAT) malware, are becoming more widespread. At the same time, cryptomining botnets Smominru and ADB.Miner proliferate. It is without doubt that we are transitioning into an era of more sophisticated and multipurpose botnets, and new detection and defensive mechanisms may be required.

The aim of the Special Issue at hand is to compile and publish solid works on the broad area of botnets, considering this threat from a both offensive and defensive perspective. We seek novel contributions from researchers, industrial practitioners, academia, and government agencies. Only technical papers describing previously unpublished, original, state‐of‐the‐art research, and not currently under review by a conference or journal will be considered. Surveys, simulations, practical results, and case studies are also welcomed.

Possible topics of interest of this Special Issue include but are not limited to:

- Botnet topologies and architectures;
- IoT botnets;
- Advanced C&C channels;
- Detection and mitigation of botnets;
- Economics of botnets;
- Legal issues pertaining to botnets.

Guest Editors
Dr. Georgios Kambourakis, Dept. of Information and Communication Systems Engineering, University of the Aegean, Samos, Greece
Dr. Konstantinos Kolias, Dept. of Computer Science, University of Idaho, USA