Weird "chain link" noise in iPhone 5s photos

In some of my iPhone 5s photos, there is an odd artifact. It almost looks like a distorted chain link fence. See the pic below. Has anyone else encountered this? Note that it also appears in some color photos (with no filters or HDR applied). Of course, if no one sees it in the pic below then I'll know the problem is that the pic and my monitor are producing a moire pattern.