Sorry, you are correct about US intervention in Afghanistan. I intended to limit the scope of my response to the Eastern bloc, not the entire Soviet sphere. Poor choice of words on my part.
The reason I can be pretty sure there wasn't much US involvement in Eastern bloc revolutionary movements is that these movements time and again followed one of two patterns:
A. "Reformist"
1. Trusted, committed Party members have falling out with Party Secretary, who is heavy-handed/incompetent/annoying.
2. These Party members (usually Politburo) force out the Party Secretary and promise to get the worker's state back on track.
3. These new leaders (to the surprise of everyone) actually become popular by forcing out the hated leader and promising reform.
4. The non-elite classes (i.e. those not in the Party) get a little too excited in the midst of this public euphoria, and start calling for cheaper meat, less overbearing local Party hacks, freely-elected union representatives.
5. The Soviets march in.
B. "Dissident-led"
1. A small group of self-proclaimed dissidents publicly and repeatedly denounce the regime.
2. Because of this, they lose their (usually) intellectual, white-collar jobs, guarantee no secondary education for their children, endure frequent jail stints and get assigned back-breaking physical work.
3. Nevertheless, they refuse to back down, and instead continue their public activities.
4. The economy gets bad/a rally is organized for a slain WWII hero, and 10k-15k people strike/protest/rally in the streets of the capitol city. Anti-communist chants inevitably occur, and someone gets shot.
5. The shooting, and the Party's embarrassment about it, encourages more people to protest and gives them a reason to protest. Soon as much as 1/4 of the population is in the streets on any given day.
6. The Soviets march in/Gorbachev writes off the Eastern bloc.
Neither of these patterns is especially useful/conducive to US interests. The first severely damages right-wing interests; here is an example of the people of a Soviet puppet state showing trust and affection in their political leaders. If it had worked -- if Hungary or Czechslovakia had transformed into something closer to Sweden or even Yugoslavia -- the meme of socialism as perpetrator of evil would be tarnished. It's also difficult to generate political enthusiasm by more than a few hundred people. That just doesn't happen, no matter how much money/support you give.
The second pattern is even more difficult to produce. Anyone willing to be bought off is a rational actor, and in 1977 nobody believed the Soviet Union was going to disappear anytime soon. Why would you give up all earthly comforts for a future that would likely never come?