I'm not aware of any Western-supported militant groups active in the Eastern Block itself that enjoyed anywhere near the level of financial and logistical support that the Red Army Faction was given by elements of the East German security apparatus.

There were numerous political and military groups that at times received varying levels of support from the CIA and other Western intelligence agencies. There many many different groups that the U.S. and other Western powers gave covert or overt support to that were actively mainly as proper armies or factions in a civil war. Examples sometimes labelled as "state-sponsored terrorism" include the Conrtas in Guatemala and Operation Gladio in Italy.

Honestly, the closest thing is probably the various forms of support the United States provided to insurgent groups in Afghanistan in the 1980s. More controversially, some Russian groups have alleged that the Americans provided covert support to various Chechen rebel groups in the 1990s. I am unaware of any evidence that this is true, but it isn't totally beyond the realm of possibility.

I How are you defining terrorism? Definitions which the US uses to classify groups like Greenpeace as a terrorist organization or like the popular image of violent criminals? Because if the former the union Solidarity in Poland got a lot of support as did various color revolutionary groups like in Czechoslovakia and the US used covert means to destabilize Yugoslavia. But I'm not aware of any specifically violent terrorist groups sponsored by the US. The USSR also accused the British and French of funding saboteurs and having agents lay mines.

I think an issue for the US doing something like that is the East Bloc tended to have a less open civil society and while publicly available information and media was generally pretty reliable in terms of facts, alternative viewpoints, which may or may not have been lies (or truths that were inconvenient for the ruling party) depending on the context, we're more directly suppressed. The US and it's allies also suppressed some media directly but since most media in the public sphere and with the greatest reach was pro capitalist anyway given who it was owned by, but subversive ideas were more able to spread and so there was a more fertile ground for groups like the RAF and Weathermen. Not to mention contrary to popular mythology in the US people had pretty stable and secure lives in the East Bloc with a fairly decent living standard for most of it's existence. It only started to stagnate in the late 60s with the failure to improve the central planning apparatuses with cybernetics and computers because it was a political threat to the bureaucracy and a gradual transition in most of the East Bloc to forms of market socialism like with the Kosygin reforms and Hungarian "goulash socialism" that in the long run took on the worst of both market and command systems despite short term benefits (these were very different from the Yugoslav model which had the benefit of autogestion and more transparency). In the West the ground had been laid by socialist and communist institutions for almost a century where in the east it was only near the end that organizations like Solidarity could provide the scaffolding on which to create a successful terrorist movement.

Americans did aid the IRA weirdly enough which was moving against a US ally, so there is precedent though.

EDIT : adding on to this, at the risk of pathologizing terrorism, according to everything I've studied, terrorists and terrorist organizations really don't exist to fulfill their stated aims so much as perpetuate themselves as organizations, provide networks of solidarity for disenfranchised and alienated young adults, and give a sense of purpose. They largely emerge as splinters of larger more mainstream movements and institutions which have lost legitimacy or don't meet the needs of socially estranged youth. You need an established countercultural/oppressed (be it Christianity, Marxism, Liberalism or fundamentalist Islam) ideological structure (or at least with a perception of oppression against it) with organs that perpetuate it, a means for this ideology to reach disenfranchised youth, and radical groupings which appeal specifically to this demographic. So providing material aid by a state can help facilitate something like this but the conditions need to be there. Not to mention in the USSR and much of the East Bloc, Fascists and other groups that might have sided with the west were pretty severely suppressed immediately after WWII.

EDIT 2: Also the US did support right wing violent terrorists in Italy after WWII to target leftists and prevent the Communist Party from taking power.

There were also the Forest Brothers who operated in Estonia, Latvia, and Lithuania after the end of World War II in the 1940s and 1950s and are believed to have numbered around 50,000. They were largely run to ground by the early 1950s by the KGB (assisted by moles such as Kim Philby), although some continued to fight on beyond that time period.

Tibetan rebels who fought China in the 50s

http://www.amazon.com/CIAs-Secret-Tibet-Modern-Studies/dp/0700617884