This is the ascent of Mt. Kazbek on skis. Please note that this is something done after acclimatizing on several tours from Altihut or Meteohut. The route more or less follows the summer route for Kazbek and descents via the same track.
The track passes both Altihut and Meteohut, which can be used as accomodation for the ascent.
Kazbek is a high mountain and should not be underestimated in both summer and winter. Glacier safety equipment and full knowledge of crevasse rescue procedures are absolutely mandatory. If you are not an experienced mountaineer, hire a guide.