Looks like The Cosmonaut is indeed a Frostclick file: http://www.frostclick.com/wp/index.p...the-cosmonaut/

There's some info in this older thread - maybe it's the same kind of thing that shapeshifter910 is talking about:
http://www.gnutellaforums.com/frostw...w-malware.html

I remember ages ago there a similar thing happening with LW, where a file (in that case the file in question was the latest LW version) in the .networkshare folder was being shared without users' knowledge.