Like anti-viruses programs, xTrap is launched along with CrossFire and continue manipulating memories while CF is running to detect suspicious processes that try to interact with CF.exe. If something goes wrong, xTrap will close CF and gives out an error messenger, telling players the possible reasons and general suggestions to fix it. Accessing Process viewer like Task Manager is also counted as suspicious activities (This is xTrap's self-defense module to avoid being "killed")
Though not as effective as many people think, xTrap is actually better at detecting and blocking hack tools, some that GameGuard can't detect. Naturally hack tools are updated faster than xTrap because hackers are everywhere, while WiseLogic must work on updating their xTrap for every publishers, so xTrap often falls behind when coming to updates. However, xTrap is still a necessary tool to help protecting CF against popular and public hacks, which many people can use for free.
To date, only CF China does not use xTrap. They have their own anti-cheating program called Tencent Protect, which works similar to GameGuard, but much more effective due to in-game file checking. This process requires powerful computers however, so players with decent PCs may have to wait a bit long before the game is loaded.
Unfortunately, XTrap can only be run on a computer's administrator account, so it is not possible to play CrossFire in Guest accounts or Standard users' accounts.