How do I stop continuous pop up alerts for virus on my iMac OS running High Sierra 10.13.6?
I’m experiencing an issue of small banners of the same theme briefly and repeatedly appearing on the screen regardless of which application is in use. They are all about an infected virus situation. This started when a webpage was clicked on and the results was some page that was unrelated to the advertised link. I took no action on this page but backed out of it quickly. I have not downloaded any anti-virus applications since I had understood that this was not necessary for an iMac. Obviously, it must be some sort of scam.
What action can be taken to eliminate these banners?
If there is some veracity to this announced virus, is there a way to check the health of the system?
Here's a sample of the banners:
My iMac OS is High Sierra 10.13.6. Late 2009.
[Re-Titled by Moderator]
iMac, macOS 10.13