Well, I guess it was inevitable. People, including yours truly, are getting spam ads on the Mac OS iCloud Calendar. The latest is some type of RayBan sunglasses ad. I received this ad on my calendar as well. There is quite a bit of discussion on how to get rid of this stuff.
The ad just pops up on your calendar as an Event. I already deleted my instance or I would who you what it looks like. It seems to be associated with the Apple iCloud email account. Some people have devised a way to make a spam calendar and then direct all this spam to that calendar. However, I think there may be an easier way. It goes without saying, Apple should fix this problem.
If you are having this issue, then try the following. Login to your iCloud account (www.icloud.com) online (you must use a Desktop web browser for this, it will not work in an iOS browser). Select the Calendar from the displayed icons. In the Calendar, click on the small gear symbol in the lower left corner of the window and select “Preferences:”
In the “Preferences” area click on the “Advanced” tab:
At the bottom of the “Advanced” window you will see “Invitations:”
It will be set to “In-app notifications.” Just change that to “Email to youremailaddrss” and click “Save.” Now, supposedly, these type of invitations will be sent to your email. Then, you can train your spam filter (In my case SpamSieve) to remove it.
By the way, if you are using the excellent BusyCal app for your calendar you can just right-click on the spam event and choose “Cut Event.” If you try to do that in the Apple Calendar app it does not always work.
I have not been using this method for very long, we will see if it works. The bottomline is Apple should just fix this so we do not have to go through all these machinations.