Storm Worm, Encryption, Disruption, and more...
We also found out that the "authentication" used by Storm is very weak: The four byte XOR key is a simple obfuscation scheme, whereas the 64bit RSA needs a little bit more work to break the crypto. Actually we published our results back in April 2008 during the First USENIX Workshop on Large-Scale Exploits and Emergent Threats (LEET '08), a fact that some people seemed to have missed. Frederic Dahl also summarized all of these aspects in his diploma thesis which was published in March 2008.
My presentation from back then is available as "Measurements and Mitigation of Peer-to-Peer-based Botnets" and I also did a talk during the work-in-progress session on the crypto aspects of Storm Worm: "Other Aspects of Storm Worm".
Nowadays Storm Worm is not a very interesting botnet, we actually stopped the crawler several months ago since not many infected machines are still online in the network...


