iOS 11.4 (build 15F5037c) is an official Apple over-the-air update for the iPhone 8 (GSM), released on 2018-04-02T17:06:49Z. The update package is 324.99 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: bd537eaef9b133d7a528e4217338f9724c03047d.zip.