I use Avast Mac security software I have just found exactly what u have on your mac, my youngest son, playing on Roblox clicked on the mackeeper ad/message re u have a virus... on that site & now i have it...got rid of it though using Avast. https://www.avast.com/free-mac-security Very happy it found it.
This Avast seems to be very through, still using it doing whole scans or custom scans on my HD & it has stopped weird things with 'Smart mac ads' popping up in Chrome over other sites. Also an extension I was using, since deleted, Http everywhere - it might work for some but in my experience, man this thing me a lot of grief, slowness, & not loading pages...deleted it. I'll post further experiences & found bad stuff as I go here. Also I found malwarebytes didn't find anything yet. I keep using it first then Avast. 8^)
Found tonight & deleted:
Mac Pirrit-D [Adw]
/Library/rustling/rustling
/Library/wavably/wavably