Unknown person pushing events to my Calendar

See this similar themed thread -- How do I block spam calendar invitation emails?

You could also do the following --

1. Create a new iCloud calendar - call it "Junk"
2. Move the spam invite to the new Junk calendar
3. Delete the newly created Junk calendar with the spam appointment in it

I had this happen to me, but it was in Chinese and it sent the invite to every day on my calendar. It is linked to your icloud account. Turn off sending push notifications from icloud. You may also need to turn off sending push notifications from icloud on your phone and also turn off push notifications from calendar. It is a pain to have to sync your phone and computer calendar manually, but it is the only way to keep these spam invitations from getting in .

I have the same issue and the problem is that you cannot delete them. They are events that can only be deleted by notifying the sender naturally we do not want to do that. Like the above poster, I got the Chinese event now showing up everyday on my calendar.

Any assistance would be appreciated.

Simply delete them and consider your changing your password to something stronger, using a third-party password application such as LastPass or 1Password, and enabling two-step verification or two-factor authentication.

Somewhat of a workaround in this similar themed thread -- Spam Calendar Invites

Not sure if the PC version of iCloud would allow for this though but it's worth a shot.