The network is riddled with auto generated files ...some harmful and some just a damn nuisance. The thing to remember is that most of these nasty files are under 1MB and a programme file is likely to be Well over that size.
At the top of the forums there are stickies and other useful things to read. I'm not sure if you strayed into Bearshare by mistake .. or if you are using Bearshare, but the ~Limewire forums have lots of information on various subjects
http://www.gnutellaforums.com/showth...threadid=41432
and
http://www.gnutellaforums.com/showth...threadid=33325
should help.
It is VITAL you use anti virus and anti spyware software All the time!
And it is very risky downloading programme files unless you are absolutely sure what you are doing