iOS 8.1.1 (build 12B435) is an official Apple over-the-air update for the iPhone 4s, released on 2014-11-17T18:06:06Z. The update package is 1.43 GB. This is a delta (partial) update that requires 5.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: aed339b56d3730b779a7ae89f3a3dd1173872940.zip.