Virtual Honeypots: From Botnet Tracking to Intrusion Detection

Something that is interesting, but rarely seen is botnet owners discussing issues in their bot channel. We observed several of those talks and learned more about their social life this way. The bot-herders often discuss issues related to botnets but also talk about other computer crime–related things or simply talk about what they do.

Our observations showed that often botnets are run by young males with surprisingly limited programming skills. These people often achieve a good spread of their bots, but their actions are more or less harmless. Nevertheless, we also observed some more advanced attackers, but these persons joined the control channel only occasionally. They use only one-character nicks, issue a command, and leave. The updates of the bots they run are very professional. Probably these people use the botnets for commercial usage and sell the services. More and more attackers use their botnets for financial gain. For example, by installing browser extensions, they are able to track/fool websurfers, click pop-ups in an automated way, or post adware as presented in the previous section. A small percentage of bot-herders seem highly skilled. They strip down the software used to run the C&C server to a non-RFC-compliant daemon, not even allowing standard IRC clients to connect.

Moreover, the data we captured while observing the botnets show that these control networks are used for more than just DDoS attacks. Possible usages of botnets can be categorized as listed here. And since a botnet is nothing more than a tool, there are most likely other potential uses that we have not listed.

With our method we can shut down the root cause of all of these types of nuisances, and hence the preceding methodology cannot only be used to combat DDoS.

To find out how the authors were able to make such observations about botnet behavior, read all of Chapter 11: Tracking Botnets (.pdf)