I’ve previously written about the spamming industry, especially the cooperation between virus writers and spam senders. Unknown authors conducted an analysis of the Sobig worm and identified the individual likely responsible for that particular malware. Coincidentially, it seems to be the same person also responsible for the Send-Safe ratware.
The analysis is an interesting read in computer forensics and seems pretty convincing (although it can not be a proof, obviously).
The PDF can be found here and here plus as a locally mirrored copy.
Via F-Secure