for future reference, .zip is a compressed archive that could contain anything, not a media type. (and it irks me so much when people put compressed media in a compressed archive, but oh well)
but it's strange, I wouldn't think you could get a virus simply by opening an archive unless it was exploiting a vulnerability in a certain archive handler.
haha, did this archive perhaps have a freeandlegalmusicdownload.mp3.exe file in it?
and is this a bios password or windows password that it wants?