Free-to-play Arctic Combat 'borrows' one of Counter-Strike's maps
As PC Gamer says, a few of the dimensions are off and a few crates have been moved, but from that opening spawn ramp down to the middle chokepoint and the side hallway, there's no question this is a very familiar map. Arctic Combat is currently in closed beta, though once Valve catches word of this, you might not see "Sand Storm" playable any longer.