This Unknown Status icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,400 icons, all in the same style and quality.
It's a logo of a circle in the middle and then on the right and left two smaller circles on each side in a straight line and on top and bottom one smaller circle in a straight line to form sort of an equal sideways cross look to it.
Related to Unknown Status Icon
Related icons are the icons with matching tags, as well as all messaging icons. All icons are in the same flat style. You can either download free PNG icons or buy SVG vectors