Network cabling in crawlspace

I am going to run Ethernet cabling in my crawl space and was wondering if I have to have outdoor- rated cabling or if riser cables would be ok. Crawlspace is not sealed, it is open to the ground. Cabling will hang from joists but will they still be subject to corrosion? I assume that since it is just dirt that there will be moisture.
So if I do use outdoor- rated cable is it fire-resistant enough to run through the walls (no plenum runs)? Thanks!