The SSRG (Ob"yedinennaya sovetskaya sotsialisticheskaya razvedyvatel'naya gruppa) was a Soviet equivalent to UNIT. In English, its name translated to the United Soviet Socialist Intelligence Taskforce. (AUDIO: Kaleidoscope)
According to another account, a USSR contingent of UNIT was formed in the 1970s. It was widely believed to be an arm of the GRU (Soviet Military Intelligence). (PROSE: An Army of Shadows)