Do you have any evidence that Russian espionage backed the far left before 2006?
And no, they didn't really change who/how they backed for 20+ years.
Given "before 2006" includes the entire history of Soviet espionage, that's kinda like demanding evidence that the sun rises in the East. It's very obvious that Soviet espionage would have supported far-left groups in the West, so if you want evidence you should probably do your own research.
Now the post-Soviet period in that range, 1991-2005, is a different question.