If you are specifically looking for a KV.bin for a JTAG/RGH modded console to unban it or for development:
There have been instances of modding tool developers receiving cease-and-desist letters and, in rare cases, criminal prosecution for distributing tools that facilitate theft of services (Xbox Live). kvbin xbox 360 download free
Fortunately, there are legal alternatives to accessing Xbox 360 content: If you are specifically looking for a KV
Here's how the logic works (though we do endorse this): in rare cases