Oil on engine block?

https://preview.redd.it/s04wunbpn35g1.jpg?width=2268&format=pjpg&auto=webp&s=6d6464fb78cf1844c8f71885d08f8eb1fcc5ad8a

2016 Ecoboost Premium, 83xxx miles, regular oil changes at 3000mi

I've noticed this residue on the block for a while now and wondering if anyone else has encountered this issue or if it is a sign of a failure of sorts that needs to be fixed. I've read around that sometimes it may be due to a bolt that needs to be tightened, but I am not sure if this applies in my case. Any advice would be greatly appreciated.