Joe Stewart from the Conficker Working Group has created an eye chart that allows for online identification of Conficker B and C infections. The idea of trying to load content from sites that are blocked by Conficker is really smart. We wrote our own page based on their method with the goal to make the results as clear as possible (note this only requires a substring match on a pattern in Conficker's blacklist, rather than a complete domain name match). This detection method should be more reliable than network scanning based tests. Happy scanning!
Felix & Tillmann