Edinburgh Napier University

  Botnets are one of the biggest cyber threats. Botnets based on concepts that used for the development of malware or viruses before origin of the Internet in 1990s. Botnet is a form of malware controlled by a Botmaster using Command and Control (C&C). Since emerging of one of the first botnets PrettyPark in 1999, it has been a significant enhancement in last decade for botnet development techniques by hackers. Botnets of current age are with features such as P2P architecture, encrypted traffic, use of different protocols, stealth techniques and spreading through social networking websites such as Facebook and Bebo. With enhancements in botnet development, the objectives of cyber criminals advanced to get financial as well. ZeuS is one of the well known botnets of current with a main target is to get the financial gain. It uses advanced botnet techniques such as encrypted traffic, use of HTTP protocol and stealth techniques to hide itself from the OS. Overall objective of this thesis is application of botnet analysis and detection techniques on ZeuS bot to demonstrate that how these techniques are applicable to other modern botnets such as KoobFace, Torpig, and Kelihos etc. ZeuS code leaked in May 2011 to open the doors for hackers to utilise techniques used by ZeuS to develop new bots and for researchers to learn the internal working of one of the modern botnet of the current age. In this thesis, “ZeuS toolkit with Control Panel (CP)” is used. It contains tools to create a ZeuS bot executable with user defined configuration and ZeuS Control Panel (CP) developed in PHP and MySql, to install on a machine to act as a ZeuS “C&C server”. Ethically, according to “CSSR: British Computer Society Code of Conduct”, ZeuS botnet analysis is performed in a virtual environment with two machines i.e. “Bot victim with HIDS (Host Based Intrusion Detection System)” and “C&C server” that are isolated from host machine running VMware and the Internet. Bot executed to infect “Bot victim” machine with ZeuS bot to convert it into a “zombie” being controlled by “C&C server” machine running ZeuS Control Panel (CP). ZeuS bot analysis performed in three layers i.e. binary, application and communication layer. On binary layer analysis, reverse engineering tools used to reverse engineer the ZeuS executable to explore its internal. ZeuS reversed engineered C++ code by REC was not in a meaningful form. It indicates that ZeuS binary obfuscated using some algorithm. Only basic information i.e. version and header information for ZeuS bot executable could be found using PE Explorer tool. On application layer, during ZeuS bot execution, all activities related to threads/process, file system (.dll files accessed and files created) and registry changes captured using Procmon. Important information captured by Procmon is creation of a copy of bot executable (sdra64.exe) and data file “user.ds” created in windows subfolder “/system32” and in registry “Userinit” key modified by ZeuS to enable the ZeuS execution before Windows GUI appears (execution of Explorer.exe). On communication layer, packets during bot synchronisation with botmaster and bot commands sent by “C&C server” to “Bot victim” captured for to create rules for HIDS for signature based detection on “Bot victim”. These rules implemented and raised alarm as expected successfully. Anomaly based detection requires “learning” or profiling that requires interaction of machine on Internet. Ethically it is not possible in isolated virtual environment. DNS based detection and process to reveal a “rootkit” that modifies MBR (master boot record) of the hard disk, is not applicable for ZeuS analysis. Literature review of this thesis covers all aspects of botnet analysis and detection techniques regardless of that they are not applicable in this project ethically or ZeuS bot does not support them. Objective of providing this information is to give an overview of all analysis and detection techniques that are applicable to the modern botnets of current age.