The Russian Federation (Russian: Российская Федерация), commonly referred to as Russia, is a neighbouring country of both Chernarus and Livonia. Russia is the legal continuator of the Russian Soviet Federative Socialist Republic (RSFSR), in which it declared state sovereignty from the Soviet Union in 1991.
There are a few direct references to Russia in DayZ - it is inaccessible and does not appear in-game. However, there are references to Russia on various road signs - one referencing the capital city of Moscow outside Lopatino, one pointing to the Russian border at Grozovoy Pass and one pointing to Kaliningrad outside Topolin.
It is likely that various weapons, ammunition types, clothing and vehicles, such as the KA-74, 5.45x39mm Rounds, Gorka clothing and the M3S, found in South Zagoria originated from Russia and are present due to the region's past civil war or as aid sent in response to the outbreak
The Russian Learning book has the borders of Russia with the Russian tri-color flag and the Russian Cheat Sheet book has a picture of Saint Basil's Cathedral in Moscow. The BK-18 rifle has the words "Made in Russia" inscribed on the side of the file.
Sign at Grozovoy Pass pointing to the Russian border (ДЫНЧАЛ (РУ))