iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-05-29T17:15:59Z. The update package is 721 MB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d0e87a234b5117d0127d5a85bfdcf23e54408900.zip.