iOS 11.1.1 (build 15B150) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2017-11-09T18:09:29Z. The update package is 1.12 GB. This is a delta (partial) update that requires 10.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0b9c26ffb95c9ede67f9be04393897858afaed0b.zip.