Drifting mouse cursor I have a Mac Book Retrina Pro. 
My mouse seems to drift to the right of screen all by itself. It doesn't matter if I am using the track pad, a bluetooth mouse or a USB external mouse (or no mouse at all).

It makes it very hard to scroll using the scroll bar arrows, because the mouse drifts while clicking.

How can I fix this?

I have searched on Google, but all the threads are from 2011. The consensus was then it was a software issue, but of course the OS is different now (I am using 10.11.2)
Did you try disabling the Trackpad? One of my colleagues had this exact problem, and found out that it's actually an issue with the trackpad.