Should add that this can only occur if you haven't updated your phone in over a year.
If you were fully updated to the latest iOS last October and got infected, it would keep you infected. They also said they found the malware has been deployed in the wild since at least 2019 and this is the first discovery o. f it. And it appears to be a fully remote, stealth infection against all iPhones.
I'm no expert on security (or iOS) but it sounds pretty much like worst case to me.
Only the top of the iceberg is being visible to public if not less.