To be clear, that's with respect to regime change, not general interference like biological warfare or mass bombing campaigns, slaughtering civilians, etc. Or other standard US war crimes against lefties worldwide.
“Killing Hope” was written by former intelligence officer Bill Blum (think that was the name) and details such operations (though not limited to socialist countries).
I’ll try to find some links on the subject and edit my reply to include them but it may be a day or two.
AES countries are not bastions of perfection, every country faces struggles and works to overcome them, and Socialists recognize this. At the same time, this post is specifically referencing US sabotage, which exists at a far higher rate for AES countries.
While true, it's not what OP asked for. There have been a range of cases of both, and I'm not just referring to the CIA's X number of attempts to kill Castro.