Hi
I have just noticed an incredibly weird icon in my mac application screen when you press the F4 button. It's labelled adblock plus, but does nothing when I open it, does not appear in my applications folder and cannot be deleted. I am therefore worried, and you will understand when you see the picture below. Sorry for the bad wording, I'm about to go to bed and extremely tired. Many thanks for anyone's help.
https://pasteboard.co/GV3mEX7.png