In the modern digital age, the volumes of information security threats are increasing day by day. Recent malicious threats are intended to get financial benefits through a large number of compromised hosts-called bot. A group of bots network called botnet is responsible for sending spam emails, DDOS attack, identity theft, key logging and copy right violation. Botnet becomes the platform of new malicious attacks and boost the capability of the old malicious software's. Most of the threats have the ability to evade new commercial antivirus, network intrusion detection systems and firewalls.In this book host based botnet detection mechanisms are investigated using honeypot technology. Honeypots is a highly flexible tool to prevent, detect and monitor the information security threat. A physical or virtual honeypot can be placed with all other production computers or servers of any organization to get the detailed picture of network attack activity from outside. On the other hand honeypot can discover vulnerabilities and compromised host of an organization by analyzing the network traffic.