Left cherries on the counter for a year.?

Yuck, I can't imagine why somebody would have left something like that for a year on a counter. I shudder to think of how filthy your kitchen must be. They probably did not mold because they were very acidic. They turned brown because they oxidized, The process of fermentation probably caused the bacteria to consume more gasses than they produces, hence the vacuum. So you sort of made a type of nasty cherry wine or liqueur (no, don't drink it).

My question: what is keeping you from just dumping the whole thing into the trash can, unopened? If you are curious, just take it out in the yard and pop it open, but be prepared for some serious stench.

Are you planning on drying them out to smoke them and get a buzz? Why can't you throw the container away? Is it a family heirloom?

Decay. You should probably take the container outside and open it, take a hose to it.