Greetings:

Virtually all virus writers work alone. It's the standard profile. I did a whitepaper about our research on them a few years ago for NIPC. I'll try to dig it up later today, and post it if I find it. Out of all of the research that we have done, I was most intrigued by these guys.

As a side note, I think it is VERY obvious that those variant creators are not the same folk as the creators of the originals, as that Zdnet article would leave you to believe. Those little messages do not fit the profile of these guys at ALL.