Here i present you a cool tool made by sonicrules1234 named MCnostalgia2. Currently it works with 1.2.5 and gets updated very soon after MC is updated. Just make a new folder of it on the desktop, run the exe file and follow the intructions and you will have a clean, untouched MC.
Important: back up your saves, villagers for example won't work with MC 1.7.3 beta

Virusscans:
MCNostalgia2.1.2.zip - Jotti's malware scan
https://www.virustotal.com/file/9555...is/1338656067/