There are two abusive short messages on my friend's mobile phone showing my number, but I didn't send them to him. What happened?

You may be infected with a mobile phone virus. Ignore unknown text messages and phone calls. It's easy to catch a virus. I remember a news from CCTV a few days ago that a person's mobile phone was infected with a virus, and within a few minutes, more than 2,000 text messages were automatically sent. Until the mobile company came to the door, the single ticket was several meters.