Why does my mobile phone automatically send and receive text messages online?

I use N70, and this may happen when a smart phone downloads something from the Internet or transmits something through a data cable. My method is to call 10086 directly and tell them to help me turn off the online function that can be confirmed by SMS. I wish they had turned it off, and I didn't bother to check if there was a Trojan horse in my phone. This is convenient, it can be solved by a phone call, and it will not affect the sending and receiving of short messages such as bank card arrival and payment.