vbulletin skins?

I spent majority of my time on the computer today derping around.  Other than that I decided to take a break from wp and check out how vbulletin skins work.  These two sites help with understanding how  a skin works:

• http://www.vbulletin.org/forum/showthread.php?t=124576
• http://www.vbulletin.com/docs/html/main/stylesintro

I can only read and not actually try this stuff out today because I don't have a nulled vbulletin to run on my localhost and TPB is down for whatever reason.  I don't trust the torrents from other sites either like torrentz.eu and kickass torrents.  The thing that makes me nervous about downloading so many things is opening a virus and having all my account data stolen.  Sometimes when I'm really paranoid, I convince myself that I already have a virus and go crazy with scans/checking folders/processes where it could possibly be.  It'd probably be a good idea to ask the experienced members on HF if my comp is infected because I feel my paranoia coming in again.