Just look more than half way of the thread and you'll see a list of a bunch of hacks that are undetected. The threads that are crossed out are DETECTED. The ones that are not crossed out, MIGHT not be detected. If you want to take precautionary steps, you want to always look at the last few comments and see if people might be complaining about getting banned, or the hack might not be working.
For a hack you will also need an injector, which you can find in this section here. CrossFire Spammers, Injectors and Multi Tools - MPGH - MultiPlayer Game Hacking
You need to download the hack, and the injector. After that extract both the hack and the injector, then open the injector. From there, load and browse around for the hack which came in a dll file. Add the hack to the list, and set the process to crossfire.exe. Set the injection type to manual. Now as soon as HGWC is done loading, then you want to inject from that moment.
There is another type of hack; exe files. You put the hack in your crossfire directory which is located in C:\Program Files\Z8Games\Cross Fire. And all you do from there is copy and paste that hack and run it. It'll open crossfire up for you with a menu or some sort of features - depends on the hack.