Can I just spray some bleach on it or paint over the mold?

While there are still some sources that advocate using bleach for mold clean-up, we do not recommend it in most situations and for several reasons.

In published resources chlorine bleach does NOT effectively kill mold, especially on porous surfaces (drywall, wood, etc.) and actually promotes regrowth by adding water to the material and changing surface texture. Bleach can be an effective sanitizer and stain remover from non-porous surfaces but not so great at killing/removing mold. Popular stain sealer paints like KILZ, etc are also not effective if you have not first removed the moisture source and PROPERLY removed the mold. If the offending components have not been resolved it will likely come right through the sealer paint.7,8

 

 

7 NORMI - https://www.normi.org/articles/bleach-mold.php
8 EPA - https://blog.epa.gov/blog/2015/04/when-it-rains-it-molds/#comment-302336