iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-05-29T17:16:00Z. The update package is 240.63 MB. This is a delta (partial) update that requires 11.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d12bd21a77ccfb1e98d19ca77afa17b2b5751d1a.zip.