Nimda
The worm's name comes from the reversed spelling of "admin". F-Secure found the text "Concept Virus(CV) V.5, Copyright(C)2001 R.P.China" in the Nimda code, suggesting its country of origin. A computer in Canada was responsible for an October 11, 2001 release of infected emails alleging to be from Mikko Hyppönen and Data Fellows.