How to get rid of spam modal dialogs in Android?

Question

Android

Good afternoon.
I don't use Android and it's a mystery to me where such incidents can appear in a modern OS?:

Windows like this appear once a day on my wife's phone. To close such a window, you need to click on any of the buttons many (many, many) times.
How to determine the source of these messages and get rid of them?
Thank you!

Answer 1

In general, I found the reason for these messages. This is the fault of the Tele2 provider card . Incredibly, the provider puts spam messages in the SIM card that block the phone. I hope in the near future I will be able to burn their sim card on a sacred fire.
Solution:
- Go to the Tele2-menu application, open the Tele2 theme and click "Turn off".

Answer 2

First:
1. Perhaps I will surprise you, BUT viruses are also written under Androyd.
2. There are programs that are "free", but in addition you get different "buns" like the one you have.
3. If you install programs not only from google play , there is a high probability of installing a virus file.
I. If these messages started to appear recently - remember which programs you installed last, maybe you caught 2 or 3 points, try to remove these applications from your phone
II. If messages appear from the moment of purchase, look at what programs are hanging in the phone’s memory, stop processes that are suspicious.