How can a mobile phone send countless messages to others without knowing it?

I have encountered this situation, and there are three possibilities:

Sometimes I accidentally touch my mobile phone when I put it in my pocket, which is often the case. In this case, just install a password lock on my mobile phone.

Junk applications will be sent automatically. If unauthorized junk applications are installed, they will appear. This kind of software either secretly sends text messages to deduct your phone bill, or sends a lot of meaningless junk information to people in the address book.

Mobile phone poisoning, you can download an antivirus software to kill it.

I hope my answer can help you, and I wish you a happy life!