Rooting utilities like Kingo Root and King Root are unfortunately very popular, their advantage being the easiest way to root a lot of phone models. But that group of 'one-click' rooting apps are typically sourced out of China and often involve implementing system-level data-mining, linked to miscellaneous online servers, along with doing things like resetting your browser's home page or its default search engine.
So you while you will end up with a rooted device, in an oddly inverse way you need to apply those root privileges to also 'clean' up your system up so it's not being compromised using such a dodgy process to root your device.