Annoying message

[AGC8]

Recently I've been getting this message when I open my Samsung Clear View case or change themes I downloaded free from the Google Store. 

Could have infected my phone pressing a link from a message "Push ___"

This is the screenshot

Ideas? Like to get rid of the message "Failed to download attachment..."

[AGC8]

Samsung Messenger app says I used almost 700kb... yet when I checked my account it says I used 0kb... so I force stopped Samsung Messenger till I talk to tech support tomorrow... should be able to remotely fix this using Smart Tutor

[AGC8]

Talked to a tech suppor girl at my carriers company.. told to clear the cache and data for Samsung Messenger... the app in question... so far no more annoying message

[AGC8]

Ben a day since I cleared the cache Ave data for Samsung Messenger. The annoying bogus message hasn't returned. The 2nd time my carrier tech support girl has come through for me. Mostly they aren't that with it.

[AGC8]

Been a day since clearing the cache and data and the bogus message hasn't returned. And shouldn't from this point on.