Triggerbot

Features:
Shoots automatically when you aim at an enemy, best for snipers (especially scout) and shotguns, not that useful for full-automatic weapons

Requirements:
AutoIt (google it)
Windowed mode

How to use it:
Download AutoIt and create a new .au3 file.
Copy and paste the code from the link below.
Use AutoIt's window spy (you can also use window info, as some people don't seem to find the window spy) to find the coordinates of the middle of the crosshair ingame. This is different for each screen resolution.
Replace MiddleX and MiddleY in the code with your X- and Y-coordinates and calculate the 4th coordinate.
Save and run the script.
You can use F2 to pause it if needed.

Click here for the code! (The link goes to pasebin.com, because the format was messed up here)

This triggerbot works with every game in which the crosshair changes color. The downside of this is that it sometimes triggers when looking at red cars and such.

I created this code myself, but I don't take any credit as it's really easy to do and I'm probably not the first to do this.
This cannot be detected because it doesn't change the game in any way, it just analyses the change of color and then triggers a left mouse click.
It's a little buggy and sometimes triggers when not looking at enemies, so feel free to play around with the code to improve it!