Download iOS 11.4.1 (15G77) for iPhone 6s

You will have to note that you can only restore signed IPSW firmware files using iTunes or 3utools.

❌ This IPSW firmware is not being Signed by Apple

Firmware Identifier iPhone8,1
iOS Version 11.4.1
Release Date 2018-07-09
Update Date 2018-06-30
Sha1sum
ca9fafec703277afb8b7381a8c9d5adfe19d9eed
Sha256sum
969932ec35c7a3122936ec49e220657dfb3b1d2876e2517f4d3a0cb7a627738d
md5sum
8c6528a7b18c1f7f07008fd981145b37
Size 2.59 GB
FileName
iPhone_4.7_11.4.1_15G77_Restore.ipsw
Status

Download IPSW (2.59GB) Check device info
Release Notes

It should be noted that these are the official release notes for the from Apple

iOS 11.4.1 includes bug fixes and improves the security of your iPhone or iPad. This update:

For information on the security content of Apple software updates, please visit this website:

https://support.apple.com/kb/HT201222