Too late My couch is now shaped like a giant avocado

Is this mold? What to do about it?

Just wanted to switch to my down duvet that I bought only in September last year. I see yellow, pink, black spots on the duvet that were definitely not there before. Could this be mold? The duvet was stored in a canvas bag that lets air through, but it's stored in an attic that may be a bit damp. Can this be taken to the dry cleaner? It was very expensive, so I must save it.

(👋🏻🦋)