Well, believe it or not, there are actually quite a few of them.
The two big ones used by the Russian Military are Systema which translates to “The System” and Sambo. Sambo comes in a few different flavors, such as the variety used for sports and the version used by the Russian Military. Systema is military only, though you can find a few schools in the United States that teach it as a form of self-defense.
Systema is more about joint locking and screwing with someone’s body.
Sambo is more about grappling.
Neither of these martial systems were inspired by their southern neighbors. They are unique to Russia.