The Shadowserver Foundation reported that it has discovered 7 million unique IP addresses infected by Conficker and its variants. Tracking of the attack was accomplished by cracking the algorithm that the worm uses to find instructions on the Internet. Shadowserver then used sinkhole servers to log infected systems, and it says it is still seeing new infections in PCs today. Although Conficker s size is giant, the lack of use by its controllers have some researchers puzzled, though one researcher believes that Conficker creators could be scared by all the attention it received.
Source: https://threatpost.com/conficker-infects-7-million-systems-year-110209/72989/