This hack is legit , i used it , editied prestige, added tokens etc all worked , to see if it actually worked i closed hack and restarted COD MW3 multiplayer and the things i set are all there still, i joined a game to and it was all there to weapons and all, and i couldnt gain exp so this actually is legit.
For safety i had to edit out my in-game name.
Sadly it dosnt add weapon experience so all attachments need to be unlocked through play.