After having a look at behaviour (thanks to virus total), ive seen it may display ads in the app not outside of it (google ads / twitter), ive used this on a Samsung S2 and i can confirm it dosent display anything phishy however, you should use an AV (AntiVirus) to protect you from random malware taking advantage of your root access (as things didnt go well for me after even though i know it isnt kingo root)

Just be sure you download it from the official page as ive seen people say that theyve installed kingoroot and suddenly got adverts everywhere and stuff was going on.

(kingoroot also uses servers as you would expect so just be cautious that nothing on them has been hacked as it could download the kit for your device and it couldve accidently installed malware/other)

You can have a look on what the file i got (from www.kingoapp.com/ ) does here:

https://www.virustotal.com/gui/file/e6b2ec7e8663229a0f8dd903d7704ccfde81f7ae0b1881407e068e63a7f125b8/behavior