Urgent, has the mobile phone been hacked?

It depends on how dark it is and by what means. In fact, it is not as terrible as you said. If you hack through SMS, it's usually just a virus, and you can't do everything. After all, there are still many restrictions on SMS codes. I can only play a joke on you. There is no need to change your mobile phone number. Just take precautions. I suggest that you restore your mobile phone to the factory settings or refresh it, so there will be no problem. Don't accept files from strangers casually.