Is the described situation an attack, and if so, what are the possible consequences?

Question

Information Security

Today, at a certain point, a large number of SMS from different companies with confirmation codes began to come to the phone, and phone calls from different countries also came. If this was a planned action, and that is exactly what it looks like, then it is not clear what the organizer of all this wanted to achieve.

Answer 1

DDoS on the phone.

it is not clear what the organizer of all this wanted to achieve

For example, it will prevent you from taking an important call. Or, among hundreds of unnecessary SMS, you can skip (not notice) one necessary one, for example, a warning from a bank about debiting funds from a card, etc.
But it could also be just bullying.

Answer 2

Either registered on an unverified/weak site, or someone is trying to register using your number. I had a similar problem, it went away with time.