Yesterday I watched part of National Bird, a movie about the US killer drone program. You can read a bit about it here, and you can watch it on Netflix:
I like Errol Morris, but he has a talent for boring you in the first ten minutes (or less) of his movies, and then keeping up the lack of excitement for the next hour and a half. If you can make it through all of National Bird in one sitting, you're far more patient than I am.
The movie describes an information gathering and human termination system which is world wide. It can find anyone, anywhere and kill them any time of the day or night. Maybe it doesn't work yet in the BRICS countries, but it will once they let it in ... or construct one of their own.
Another thing the movie makes clear is that the system's top-level controllers don't give a damn about humanity. They kill alleged terrorists, innocent bystanders, and civilians of all ages and stripes, especially unarmed military aged boys and men. And they also devour their own operators (e.g., drone pilots and those who track the targets), many of whom suffer from PTSD during and following their tours of duty.
The "national bird" system IS Skynet. And it doesn't require the machines to become self aware. Its high-level controllers already have proven themselves to be ready, willing, and able to target and kill humanity with or without the assistance of a malevolent AI.
And unless we stop them, they will.