What will the message show when it is hacked?

After the message is hacked, nothing will be displayed on the other party's mobile phone.

When your short message is hacked by the other party, the other party's mobile phone will not display any tips or notifications about your short message. This is the behavior of the mobile phone system, not the behavior of the operator. You send a text message to the hacked number, and the other party's mobile phone will intercept your text message and will not display it in the text message inbox.