The bank signed a mobile phone number to receive text messages.

1. The number was leaked and stolen by criminals. 2. Someone blew up your mobile phone with a text message bomb. As long as you start the program, you will always send text messages to this number. There is a verification code, a notice, and it belongs to the whole person. 3. Your mobile phone number is often used for websites, games and social activities, so someone will buy and sell the number, which will cause you to receive so many verification codes.