Seems like someone was making a experiment with these conficker worms. i mean that analysis of conficker C basically states there were numerous implications that were added that "only as little as 15% of the original B code base untouched" so it seems to me like it was a modification from a different author who found/was infected by B and decided to use it for his/her/their own ends. of course thats just a Blind assumption

. Its kind of creepy how in the Analysis report the researchers added "It is clear that the Conficker authors are well informed and are tracking efforts to eliminate the previous Conficker epidemics at the host and Internet governance level."