Why does my mobile phone often send text messages to some strangers automatically?

It's poisoning! It doesn't matter if you don't leave the phone, but the current anti-virus software for mobile phones is easy to use and free, which is too rubbish ... In fact, brushing the phone doesn't do any harm to the phone, just like a computer downloading something from a new system ... As long as the phone downloads something online, it may be poisoned, and so does the new machine.