Is the turning warning message sent by the system?

Yes, the transfer system thought it might be stolen, so it sent a text message to warn.

Generally, we log in to the second-hand app, and then transfer money to buy me some information, because he got some of our personal information;

For example, we can ignore the mobile phone number or identity information at this time. If you think what it sends you is necessary, then we can see it. If you think it is unnecessary, you can ignore it.