BCE: Extracting Botnet Commands from Bot Executables

Botnets are a major threat to the security of computer systems and the Internet. An increasing number of individual Internet sites have been compromised by attacks from all across the world to become part of various kinds of malicious botnets. The Internet security research community has made significant efforts to identify botnets, to collect data on their activities, and to develop techniques for detection, mitigation, and disruption. One way of analyzing the behavior of bots is to run the bot executables and observe their actions. For this to be possible, one needs proper input commands that trigger malicious behaviors. However, it is difficult and timeconsuming to manually infer botnet commands from binaries. In this paper, we present a tool called BCE for automatically extracting botnet-command information from bot executables. Our experiments showed that the new search strategies developed for BCE yielded both substantially higher coverage of the parts of the program relevant to identifying bot commands, as well as lowered run-time. Keywords-botnet analysis; bot-command analysis; directed test generation; control dependence