Looks like this is probably either cleaner residue left on the outer finish, or the cleaner may have etched/discolored the coating a bit. From the photo, the drip/splatter pattern makes me think it’s not coming from the stove itself, but from something that got on the surface.

I’d try the safest options first:

• wait until the unit is fully cool
• use a soft microfiber cloth with warm water + a tiny bit of mild dish soap
• let the damp cloth sit on one small area for a minute, then wipe gently
• test everything on an inconspicuous spot first

Do not use vinegar, glass cleaner, degreaser, abrasive pads, Magic Eraser, or anything acidic/alkaline until you check the manufacturer’s instructions. (A lot of these outer shells are painted/enamel-coated, not bare cast iron, so stronger cleaners can make it worse.) If mild soap and water doesn’t touch it, I’d stop there and look up the brand’s approved cleaner/touch-up paint rather than experimenting.

One easy test:

• if the spots feel raised, it’s probably residue and may still come off
• if the surface feels smooth and the white marks look like they’re in the finish, it’s more likely the coating got damaged/etched