To be perfectly honest, there are over thirty thousand different types of spiders and its almost impossible to identify the exact spider you are looking for. I did a little research and one spider I have found is called a Sow Bug Killer its abdomen or rear section, is shaped like a peanut.
There are a couple of different species of spiders with yellow bodies and red legs. The female brown recluse spider and the orb-weaver spider both have these characteristics. It could also be the garden spider or a crab spider. There are over 3500 different species of spider, so it's hard to tell just from the colors what kind it is.