Random SIM changes

Huawei G300, Android 4.0. Anti-Theft rooted.

Hi,

I haven’t changed the SIM, but this night, while sleeping (I didn’t touch anything), Avast detected a SIM change. Half an hour later, it detected antoher change, this time back to the normal IMSI number. It’s the second time it has happen. ¿Any idea why?

Thank you