The DNS bypass was very popular years ago, but it is highly unreliable today as the servers running the exploits are often shut down. The iPhone 4s is particularly bad at this because iOS 9 handles network handshakes differently than iOS 10+.
They use a combination of the checkm8 exploit and a server-side spoof. You pay for a “ticket” that their software injects into your phone’s activation records. Iphone 4s Ios 9.3.6 Icloud Bypass
Introduced with iOS 7, was designed to deter theft by linking a device’s hardware ID to a specific Apple ID. On the The DNS bypass was very popular years ago,
Note: Software and exploits change. What works today might be patched tomorrow – though Apple no longer updates iOS 9.3.6, so these methods will remain stable indefinitely. You pay for a “ticket” that their software
Tools like Sliver (for Mac) or SSH Ramdisk scripts allow you to boot a custom ramdisk on the iPhone 4s via checkm8.