What should I do if my mobile phone sends a text message to my sister for no reason?

What did the text message send? Are they some advertisements? Or some URL links?

There is a cell phone zombie virus recently, so don't be careless. . . Or go to the mobile phone customer service to get the mobile phone.

Look out, everyone! I'm afraid to download even mobile phone applications recently. . .

Then ask your sister to uninstall the anti-theft software. . .