If you take Josephus’ historical account it would be the Scythians, which would be today’s Eastern Russians (caucasian Russians). But most interpretations of Ezekiel and all of Revelations see Magog as a metaphorical evil nation. ​

Magog is very sparingly mentioned in the Old Testament, once in the annals of Genesis (which is where the connection with Russia springs from and how Josephus supports the theory), but given the context John was speaking of and the composition of the army that sacked Jerusalem, it may have been a red herring. Just given the breadth of time that passed between when the Torah and Revelations were written. From an etymological standpoint, there were Canaanite gods with similar names to Magog, and the Hebrew of this similar word means “king/god of the time”. The Quran also uses this in Arabic to designate the same thing, referring to false gods or totemic gods.

It’s all interpretation though, and the Russian angle is interesting given their alliances and world power at the moment.