For your information in case others have this. Several days ago I began getting popup notifications in the upper right corner of my screen that would last about 1 to 2 seconds. The time between them varied from about every 30 minutes to about every hour and I could not associate it with any apps I was using. It was giving me warnings and there were several different ones, for examples:  “Your computer is being hacked”, “ You have malware in your computer”, “Your iCloud account is being hacked”,  “Your Bank Of America Account is being hacked”. That was a good one because I don’ thave an account with them, proving it was false notification.   

I contacted Webroot Technical on three consecutive days and each time I allowed them control of my computer to determine the problem. The first two failed. They third, Jeffery, found it. Wish I could tell you what it was. It had a small icon among others but no name whereas the others were named. Every time Jeffery would turn it off, it turned itself back on. He was able to delete it and I’ve had no more trouble. 

I don’t know how I got it, what it was, how Jeffery got rid of it, but if you get it you will know a tad more than I did as it was occurring.