Unwanted Spam in calendar

It is highly probable that an inadvertent click on a website link has “subscribed” an additional (unwanted) Calendar to your device - and this unexpected Calendar is exposing unwanted calendar events and sending you unexpected “spam", virus or other events/warnings. 

Given that infecting a non-jailbroken iPad/iPhone with actual malware is incredibly difficult, this technique is employed by malicious Actors to fool or encourage you into doing something untoward - more often than not, parting with personal or financial information leading to fraud or attempted extortion.

Let’s check for what’s out of place...

iOS/iPadOS13 and earlier: Settings > Passwords and Accounts

iOS/iPadOS14-17: Settings > Calendar > Accounts

iOS/iPadOS18: Settings > Apps > Calendar > Calendar Accounts

Look for an “account” that shouldn’t be in the list of accounts - as this will likely include the Calendar that contains all the unwanted events. When you find the suspect account, tap - then select Delete Account. This should resolve the problem in its entirety.

I hope you find this helpful in finding the source - and in resolving the issue if an unexpected Calendar is found.

It seems like that you've subscribed to a spam calandar.

See this on how to unsubscribe from a spam calendar

1. In the Calendar app, tap Calendars.
2. Tap the info button on the subscribed calendar.
3. Tap Delete Calendar or Unsubscribe. Certain calendars can't be removed (for example, the US Holidays calendar).