Solvedhacking minecraft server with moded launcher ?

So there is a minecraft server with a moded launcher and I wonder how you can hack it since many people do it !
When you launch the launcher, it does a verification so you can't change anything.
Also, would it require a basic minecraft client hack (like nodus) or does I need to make it ?
If you have more question ask i'll awnser them thanks

You could just change up the code to set it to launch any client you want!
Or get a other launcher and try it!

What kind of modded server is it?
You could just put the forge client hack into the mod folder and do it like that.