To me, this assertion sounds exactly like the disinformation line that the Soviets were sowing worldwide...
Could be a bit embarrassing for Kerry to say, "My KGB Station Chief told be to say..."
If I were Bush I'd be on the back-channel to Putin asking if anything could be found in the KGB archives about Kerry and his organizations. I imagine they could whip something up for a few rubles. And how Ironic it would be for Kerry to get slammed by the same bunch he supported all those years.