Kill it with fire! jk don't do that. Scrape it off and apply a anti mold/spore agent to stop it from spreading, let that set up and dry. Seal the gap between header and sheathing with a spray type sealant (flexseal?) Reattach siding and hope for the best. Just looks like water accumulated on...
Free-Tools
SAn FRancisco, CA BAy ARea
https://sfbay.craigslist.org/eby/zip/d/free-tools-construction/6256610764.html
For those of you in other areas, I'm sure there are screaming deals in your "free" section. You just have to look at ads with more than one main picture and look often. Some...
Free-Craftsman Table Saw-working condition
San Francisco, CA Bay AREa
https://sfbay.craigslist.org/sby/zip/d/free-craftsman-table-saw/6254056112.html
Nice find on the RS cabinet macgee, i hope someone on here picks it up
FRee-Air Compressor 60 gal. 2 stage, 220v. Won't last, go now!
SAn Francisco, CA BAy AREa
https://sfbay.craigslist.org/sby/zip/d/free-2-stage-air-compressor/6251566213.html
Sure didn't last, or the wife made some room for her stuff in the shed over the weekend and he didn't go to work and answered the door to the person who wanted "his" free stuff posted on CL.:lol_hitti