First off, Welcome to MPGH. To find working hacks simply go to the Combat arms main. (Located here Combat Arms Hacks - MPGH - MultiPlayer Game Hacking) and look for a thread that was posted recently so it isn't patched or detected.
For Example, This thread was made 11 hours ago so you can bet the hack is up to date and won't be detected. http://www.mpgh.net/forum/164-combat...crosshair.html You'll want to click the download button.
So now you have the hack, but how do you use it?
You need an injector.
You can find all the injectors here Combat Arms Spammers, Injectors and Multi Tools - MPGH - MultiPlayer Game Hacking
I would recommend you use PerX found at the bottom of this post http://www.mpgh.net/forum/292-combat...s-updated.html
There is a video at the top of the post telling you how to use PerX