Any applications are automatically minimized a second after launch, what about the phone?

Question

Mobile devices

Phone Samsung galaxy S6.
Android 6.0.1
C recently began to observe such a picture.
I launch the Messages application (for SMS).
It opens, but after a second or two - collapses. Now I'm on the main screen of the phone (the one with shortcuts and clock). The application itself is not unloaded from memory, it is in the pool of running applications, if you click on the "All windows" button, the windows of all open applications, including "Messages", will appear. Repeated tap on the application leads to the same result. The same is with Facebook, and with Vkontakte and with other applications.
It's like someone is constantly pressing the back button.
Then I freak out, put the phone aside. It takes 5-15 minutes and this behavior disappears, the phone works fine. Then several tens of minutes pass - hours and everything repeats again.
I did not install any left applications. Everything is from the Market.
I did a full check of the phone with a prog kaspersky internet security. Finds nothing.
Rebooting the phone doesn't help.
Helpeeeeeeeeeeeeee!

Answer 1

Got an "infection". You can do a hard reset (just in case, remove the memory card, everything on the phone will be deleted) as the easiest option or try to run the antivirus in time for a full scan (if you have time).

Answer 2

Ruslan says the matter, a hard reset should help. Alternatively, you can generally go to w3bsit3-dns.com and update your firmware, choose which is better than the standard one. If it does not help, then something with the phone itself, maybe the button closes.