A rectangular box keeps periodically popping up on my screen. It's about 6-inches wide and 3-inches high. There is a 3/4-inch band across the top. 2/3 of it (on the left side) is light grey. 1/3 of it (on the right side) is bright red. The rest of the rectangle is white, except for two small black circles, one above the other, toward the left side of the rectangle, basically centered between top and bottom of the rectangle.
This rectangle can be slid off-screen, but I can't delete it, copy it, cut it or save it. Even if I move it off screen, continue to work, then navigate elsewhere, it will still pop up again later. What is this thing? And how do I get rid of it?
I would show what it looks like (I have photographed it) but there is no function that allows me to add a jpg image to this question.