The plot thickened—it turned out that Rivest’s proposal, MD-6, had a flaw. Cryptologists in the competition had duly gone to work trying to crack the code, and one had succeeded. In early 2009, Rivest quietly withdrew his proposal, corrected it, and resubmitted it. This gave the cabal an opening. If the original Rivest proposal was flawed, then so was the encryption method for Conficker B. If they were able to eavesdrop on communications between Conficker and its mysterious controller, they might be able to figure out who he was, or who they were. How likely was it that the creator of Conficker would know about the flaw discovered in MD-6?
Once again, the good guys had the bad guys in check.
About six weeks later, another new version of the worm appeared.
It employed Rivest’s revised MD-6 proposal.