Help my xperiaT is sending messages by itself after reboot

[miss_T]

Every time I reboot my phone, it starts to sending messages to random people. Messages that U've sent before. I've already done the factory reset and it doesn't help. What can I do? It freaks me out. Please help!

 

[Sam-SonyXperia]

It would be worth while running a repair:

To repair the phone software
1. Install PC Companion on a Windows PC from Support at Download for PC - Sony Smartphones (Global UK English)
2. In PC Companion, under Support Zone and click Start.
3. Under Phone Software Update, click Start.
4. Click repair phone.
5. Follow the on-screen instructions.