The group of researchers that has been most closely tracking -- and battling -- the worm has now of Conficker's size. According to data compiled by the Conficker Working Group, Conficker has been spotted on just under 4.6 million unique IP addresses. Its earlier A and B variants account for the lion's share of that -- 3.4 million IP addresses -- with the more-recent C variant spotted at 1.2 million addresses.
The countries measuring the largest number of infections for all variants are China, Brazil and Russia.