This file definitely seems fishy. I ran it through two online virus scanners that use multiple engines to determine the probability of a file being malicious.
Virustotal reports 25 positives out of a possible 42.
http://bit.ly/VirusTotal-Recapture
Jotti found 10 positives out of 20.
http://bit.ly/Jotti-Recapture
All the scanners had different names for it, but the most common was Trojan/Compact/Generic/Win32.
I also got a warning immediately once it finished downloading from AVG saying the runtime was packed with upack. I assume this is similar to UPX exe packing, but I cba to dig through the file and figure it out.
The Winamp mods/admins should take a look at this visualization plugin,
The Recapture Suite.
(I shrunk the URLs because the permalinks to the virus sites were to huge)
pogue