[atom0s]

In terms of games detecting things, it's a matter of emulating the movement properly and not injecting the data in a manner that allows the system to tell it was not done with the actual hardware. Windows has a flag to determine if a keypress/mouse movement was injected using one of the various input API's such as SendInput.

When it comes to games, you would generally hook the method of input (often times DirectInput or standard window messages ie. WM_MOUSEMOVE) and simulate the data yourself in the flow of the game polling for the data. It's easy to do on games. With applications it can be done in a similar manner though depending on how the input is read/handled.