The one crime I bring up is the biological warfare that the US wages opportunistically. The most prominently documented was the biological crimes during the war of subjugation of Korea [PDF], where the US dropped bombs with infected insects (plague, cholera, anthrax) on Chinese and Korean civilians and armymen. The report, issued by a multinational team of scientists, strongly supports this claim. The former members of Japanese Unit 731 are thought to be culpable in these warcrimes, although it's corroborated more completely in a separate report from 1981. The pages 61, conclusion, would be of interest, as well as some photos on 709. This report was released by IADL, which the US subsequently labeled as communist, and tried to sentence a journalist who widely publicized the facts presented with sedition, and dropped charges against him after 5 years.
You can also see another instance of biological warfare in the github link which talks about a manufactured Dengue Fever outbreak in Cuba in 1981.
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.
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.