iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 6+, released on 2018-05-29T17:16:14Z. The update package is 268.04 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: 02730b2e58702b1100fd904ef00fc272f158b2bb.zip.