JS Malware?

So a friend of mine had this strange piece of code on his pendrive (probably a malware). What it did interested me is that the malware in question is written in Javascript (with a obfuscated piece of autorun.inf to infected vulnerable hosts).

Can someone explain to me what this piece of code does? It's completely obfuscated btw:
Main program (77/g66ac.js & 77/i6a6a.js): http://pastebin.com/uj0xSV1e
autorun.inf: http://pastebin.com/Aqnmtiq6

NO EXCEPTIONS