Internet is connected but connection alert keeps popping up I previously surfed the internet and went into a site that has a collection of tv series so you can watch it online, but then my mac started beeping and telling me to download mackeeper due to a virus. This happened once before, so i didn't bother downloading it again since i had it, and nothing happened after. Now my mac keeps putting pop ups that says:
"Connection alert We are having troubles. Download Hotspot Shield t..." 
I can't get the pop up to show more. If i click the pop up, hotspot shield .exe is downloaded and does not open when finished. 
My internet works fine, but the pop up keeps appearing a few minutes and covers a side of my screen. What can I do? 

I use macos sierra version 10.12.6 and google chrome
Oh and google chrome and kakaotalk(korean messenger app) works fine, but i can't seem to open some apps such as skype and parallels desktop due to no internet connection
You said you had once installed MacKeeper on your mac so this resulted in installing a ton of Malware's on your Mac but don't worry you can easily get rid of all those Malware's

Download this Malware Cleaning Software https://www.malwarebytes.com it is a very popular malware cleaning software for effectively cleaning malware and it is even recommend by Apple (an Apple senior advisor over Apple chat support suggested this software to me! ) 

Until and unless you clean the malware from your mac those messages will keep popping no matter which website you visit cause it is installed on your mac not on the web in your case