OK so I have discovered that both ends of the cord are moist. Which is odd considering my monitor has unobstructed airflow, and I have a second monitor whose cord is just fine. I guess the cord is just of bad quality? Damn you Samsung.
So right as I began wiping the connector with rubbing alcohol as suggested on another forum, the entire plastic surrounding of the connector came off in big pieces.. without much pressure. Here is a picture of it all off and the rubbing alcohol wipes:
I decided I didn't want to take a chance and I threw it out. I'll order another one and use my second monitor in the meantime.
So I guess what caused it was the combination of my room being really hot, then suddenly cool when I got my AC? How come none of my other cords were affected? I hope none of the internal parts of my hardware are damaged.