How to treat a moldy wooden cabinet?

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what order should I treat a moldy wooden cabinet?
I have an old kitchen cabinet in an unheated understair to help organise all the stuff I shove "out of the way" It's been there 20y..and I recently got a new LED light for the understair and suddenly can see! But what I saw was a veneer of mold on this cabinet. So I have taken it outside, wire wool-ed the mold off. Now do I spray it was Astonish mold blaster and then nourish it with scratch-cover/beeswax polish? Or the other way round or has anyone other suggestions? (I tend to keep using and repairing thins so I probably will not throw it out, I have after all used it for 20y and it was from my husband's grandparent's)
Cheers!

No, don't spray with chemicals.
what wood is it made from and is it varnished, oiled, painted?

Vinegar kills mould spores, so that would be the best option subject to what its actually made from.

after that, what finish do you want on it?
If' it's getting damp and with no air circulation I suspect the issue will reoccur. Can you get some ventilation to it at all?

While the weather is hot, leave outside, in shade, to dry completely. Properly completely.

I would then sugar soap it in a week and leave to dry again. Wash well with vinegar - don’t be shy here. Only then would I think about waxing again.

Empty your under stair space. Wash everything. Scrub with sugar soap the whole space. Air and dry. Wash with vinegar and air again. What’s on the floor in there? Does that need to be thrown out? That space needs to be spotless before you put anything else in there.

Get some air circulating and get some damp absorbers and dry them out regularly.

Thanks to both of you for this
I know I now have to face an "empty and clean" of the under-stair cupboard/space (groan) - thanks for suggestions as to what to use, I have both white vinegar and sugar soap in house (although the latter will require a rummage in the very cupboard requiring a scrub!)
It has a thick 18th C wall to outside, no obvious damp but does get cold in winter (pretty cool now), tiled floor, proper normal sized door to my kitchen dinner which is often left open. Everything that goes in is dry, as I hate the smell of mold on towels etc so dry things thoroughly.
I think it's just too long since I looked last (not great house wife)

"It has a thick 18th C wall to outside, no obvious damp but does get cold in winter (pretty cool now)"

Apologies if I'm stating the obvious, going off topic, etc. Both old stone and old brick don't react well to things being put up against walls at all, unless said object has ventilation, i.e. if it were a built in wardrobe, it ideally needs space behind it and above it, and/or a grille.

If you avoid putting anything you can't vent directly against thick old walls, but most importantly external walls, you'll have a far better life :)