The original minerd code is actually fine. You do have to realize that most antiviruses will flag it as a virus because of Botnet operators.
OP and second post seem to have downloaded minerd that was modified for YAC. If the source code wasn't posted, you shouldn't have downloaded it. Look into compiling source code yourself instead of downloading pre-compiled binaries. ALWAYS CHECK if source code is available.
Could you provide a link to the miner file you downloaded? The bitcointalk thread would be best. It appears as if whoever wrote that code (potentially YAC founder) did it to promote his coin. Did you guys look at the posts that were made to see what they said? Are they promoting the hell out of the coin?
TBH there's not a lot anyone could get from this PC and I am pretty reckless with this machine I'll admit! New installs are a regular occurrence.... Of course I was stupid to download those binaries, it's that whole human nature (greed) thing ya know?
P.S. I am a 1st year Software Engineering Student, haven't learnt a whole lot of programming but I do know how to compile code! F7!!!