The corsac fox (Vulpes corsac), also known simply as a corsac, is a medium-sized fox found in steppes, semi-deserts and deserts in Central Asia, ranging into Mongolia and northeastern China. Since 2004, it has been classified as least concern by IUCN, as populations fluctuate significantly, and numbers can drop tenfold within a single year. It is also known as the steppe fox, and sometimes referred to as the "sand fox", but this terminology is confusing because two other species, the Tibetan sand fox and Rüppell's fox are also sometimes known by this name. The word "corsac" is derived from the Russian name for the animal, "korsák". The corsac fox is threatened by hunting for the fur trade.