Well, the KGB ran a disinformation campaign that AIDS was created by the CIA to kill kill minorities and as part of a biological warfare research. And vaccination campaigns by US charities were used to infect people.

You'll still find conspiracy theorists have who believe this. And it has affected US relations in a lot of regions. The leader of South Africa (Mbeki) believed it and based his country's response to the public health crisis of AIDS on it, refusing drugs for the infected, for example. Tens of thousands died instead of receiving treatment. And the AIDS denialist movement in the US and abroad still cite this as truth, in some cases. It has also contributed to suspicion of healthcare workers trying to vaccinate people. Over a dozen jealthcare workers have been killed in Pakistan on suspicion of using the vaccine to sterilize people. Al-Qaeda took the rumors and ran with them, basically, attributing new and terrible things to vaccinators, not just AIDS but sterilization, for example. Nobel prize winner Wangari Maathai repeated the allegations as truth. These are allegations that likely will never go away.

There still exists the idea that the Rosenbergs were totally innocent, that it was just a witch-hunt, etc. This idea was carefully cultivated by the CPUSA, no doubt with Soviet encouragement. We now have very compelling evidence that Julius Rosenberg was definitely a spy. (Ethel's involvement was likely marginal.) In general, many of the left reactions to McCarthyism were based on the idea that it was all a big, Salem-esque form of hysteria, and this was definitely encouraged by CPUSA (which, again, was basically an outpost of Soviet policy). In truth we know the Soviets did recruit many spies and many of those accused (e.g. Alger Hiss) were in fact agents. This has definitely had a lasting effect on how we talk about anti-Communism in general. (The fact that these particular people were spies does not, however, validate the accusations of McCarthy himself — he had little actual knowledge of what was going on and was taking advantage of the situation. The fact that there were in fact spies does not justify the right position towards Communism. The truth was somewhere in between — Soviet espionage did exist but was less important and less pervasive than the far-right imagined. Sen. Patrick Moynihan argued that the secrecy of the period allowed both the far-left and far-right to fester in their darkest fantasies.)