How do I stop Pop-Up Notices from "iamnotice.com"

I have Norton 360 and am running Windows 10.  Today (July 22, 2023), I suddenly started to receive pop up notices in the lower right of my screen, all of which claim that my computer is at risk and variously show "links" to McAfee, Chrome, Windows, etc. They all show "iamnotice.com." They are frequent - every couple of minutes or so, and once I clear them without clicking on anything, they reappear shortly thereafter.  They block the right side of my screen.  I've run scans using Norton 360, and it finds nothing wrong -  but clearly my system is infected.  So, two questions - (1) how do I remove this and (2) why doesn't Norton 360 detect it? Note that I've blocked all notifications, so I'm not seeing them - but it also means I'm not seeing any notifications, some of which are useful. Attached is an image of the right side of my screen.  Thanks to anyone who can assist.

what you are experiencing is the site issue, i mean the site has ads/hijackers etc.. on it ( most likely ad revenue)

i get them on a few news sites , while annoying and sometimes misleading dont believe the claims

you are correct in being concerned

they have been around for years , some hijackers ( mcafee if i remember correct, claim to find virus or issues etc..)

and of course they want you to download there " program to fix " the alledged findings

as long as your up todate and everything shows clean you should be fine, i try to avoid the sites where the ads get annoying

You are welcome.

Good news. Thanks for posting back.

Thank you for your suggestions. I downloaded Malwarebytes, but it found no problems when I ran a scan. (I will keep it on my computer, anyway, for an added level of protection.)

Your discussion of a  "malformed ad" prompted me to check Chrome's Ad Blocker (under "Privacy and Security / Site Settings"), which indeed flagged "iamnotice.com" as sending an excessive number of notifications and which prompted me to block "iamnotice.com," which I did. I have turned the Notifications back on in Windows 10, and have thus far not gotten any further unwanted notifications from this rogue website.

It looks like you may have picked up a PUP, a Possibly Unwanted Program. While they are annoying, they do not cause damage to your system. Some people actually want the 'Features' offered by these programs. They are usually downloaded alongside a legitimate download when you do not uncheck the option for the additional download.

Norton products concentrate on malware that can damage your system, that is why some PUPs are not detected.

I would suggest a second opinion scan using the FREE version of Malwarebytes. You can find it here https://www.malwarebytes.com/premium/

If that finds nothing, it could be a malformed ad on a website you are viewing that redirects you to the phoney message trying to get you to click on something so they can get your information. Norton does not block most redirects because many sites use them for legitimate purposes. Norton uses them all the time.  To help stop these redirects, you can install an ad blocker extension into your browser.