It's four small squares, each sitting on the corner of one large square. The small squares are connected by the sides of the big square, giving it a connected look. Three of the four small squares are not shaded in and the only square that is shaded in is the small square on the bottom left hand corner.
Related to Unit Icon
Related icons are the icons with matching tags, as well as all business icons. All icons are in the same flat style. You can either download free PNG icons or buy SVG vectors