Here is a simple MW3 trainer, I was going to release a tutorial on it a while back but, i thought it was a bit pointless so instead il just leave it here, for now its stuck to version 1.0 but if you Cheat Engine some of the variables you can probably edit it also yourself. I may update this at some point in the next couple of weeks depending on how busy I am, if you want me to update it then leave a comment and that may get me to do it faster.
Source in description "MW3 trainer source.zip", if you just want the hack, then download "MW3 Spec ops trainer".
Thanks and hope its useful to you
View bottom of post for screenshot of the trainer