iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-05-29T17:15:55Z. The update package is 1.31 GB. This is a delta (partial) update that requires 10.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8eb099ec9e30b4064539ed7d733ceae91bb1b092.zip.