Thanks. So the best I can come up with for a US citizen is the following. "Agent" would be a CIA or similar operative who's infiltrated a Soviet unit to try and "turn" a General or something like that, "Assassin" would be a CIA operative who's trying to "take out" the Soviet General, and "Paramilitary" would be a CIA operative who's trying to sabotage Soviet facilities and infrastructure like fuel dumps etc.
Here's some basic differences between a CIA officer, an analyst, and a paramilitary...
Officers [NEVER 'agents', an agent is by definition a local betraying his country, an 'officer' is a government employee tasked with acquiring intelligence. It's like the difference between 'soldier' and 'terrorist'] are expected to gather intelligence, mostly HUMINT [human-sourced intel] by running agents.
Analysts are tasked with evaluating intelligence to find the 'gems in the garbage'. This is harder work than it sounds like. This could be anything from evaluating signal intelligence, pouring over satellite photos, going over agent interviews and information word by word, comma by comma, to find the actionable intelligence the government requires. Analysts also generate most of the field requests that officers need to look into.
Paramilitary do the 'muscle' jobs that Officers aren't trained for, protect officers in the field if they're under high threat, and do much of the deniable shooter tasks that intel agencies require. To put it another way, the mythical MI-6 '00' would be a paramilitary.