Botnet communicates via P2P instead of C&C

Symantec reported on a version of Zeus/Spyeye that communicates via P2P among its bot peers rather than “traditional” C&C directly to its control servers. (I put traditional in quotes because I don’t want to give the impression that detecting C&C traffic is easy.)

…it seems that the C&C server has disappeared entirely for this functionality. Where they were previously sending and receiving control messages to and from the C&C, these control messages are now handled by the P2P network.

This means that every peer in the botnet can act as a C&C server, while none of them really are one. Bots are now capable of downloading commands, configuration files, and executables from other bots—every compromised computer is capable of providing data to the other bots. We don’t yet know how the stolen data is communicated back to the attackers, but it’s possible that such data is routed through the peers until it reaches a drop zone controlled by the attackers.

Now if you are successfully blocking all P2P traffic on your network, you don’t have to worry about this new development. However, when P2P is blocked, this version of Zeus/Spyeye reverts to C&C methods. So you still need a technical network security control that can reliably detect compromised end points by monitoring egress traffic to proxies and firewalls and DNS traffic because you surely cannot rely on your host-based security controls. (If you doubt my claim, please contact me and I will prove it to you.)

But what if you have a business requirement for access to one or more P2P networks? Do you have a way to implement a positive control policy that only allows the specific P2P networks you need and blocks all the others? A Next Generation Firewall ought to enable you to meet this business requirement. I say “ought to” because not all of them do. I have written about NGFWs here, here, here, and here.

About Cymbel

Specialists in information security. Helping organizations secure their networks and mitigate the risks of modern threats.

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