somehow gotten avast spam?

dear avast team!

my wife’s screen was locked by pattern, then the kids tried to unlock her phone and then this popped up (see screenshot)
also, an alarm sounded ‘‘this phone has been lost or stolen’’
the message means this phone is safely locked by antivirus.

https://s14.postimg.org/f8clyinyp/spam.jpg

she did not install Avast at all I told her to check if she somehow did and registered with Facebook or anything else but she just has 1 email and that’s not registered.
also, I noticed it’s not showing reset pin … whatever I do nothing works when rebooting I don’t even have time to enter the sim pin code because instantly it’s showing that message
I’m also not sure if this has anything to do with Avast at all I just searched for that image and avast showed up.

any help please I’m fighting this issue for 2 days now with no luck

regards,
Marcel

Try this forum section

Avast Mobile Apps >> https://forum.avast.com/index.php?board=66.0

are you sure it is avast? different pictures here > click the blue detailed steps button and scroll down

https://support.avast.com/support/solutions/articles/5000612416-avast-mobile-security-changing-a-sim-card-on-mobile-devices-with-avast-anti-theft-installed