Need Help Making the loader

I can give you some source in C++, i made it myself.

Or you could... you know... add the dll to the resources and encrypt the compiled exe to make it harder to reverse engineer using ConfuserEx or a Crypter that supports .NET.

well, there are alot of ways you can do this. its just depends on how much exp you have. well, you can make it so that you get a loader which checks login details with a website, such as pastebin or your private website (cUrl library). If you are doing this, you will have to make a server which downloads the .dll, with a encryption key which could be generated by a pattern or a self changing encryption key, so that only your loader can download and inject the .dll, after this you will be needing to either download it into the computer or do a server injection (i cant rem the exact term for it). Then you can either delete the .dll afterwards or leave the .dll . by leaving the .dll you are risking it being cracked and leaked, therefore rem to pack the .dll and loader and also add hwid lock to the .dll, you can also do alot more stuff to the .dll like adding a encryption key like before or add a function which fucks the hack up on the second injection, but you need download the .dll again and again.

thats a loader for you.
now answering your question of only making one exe for the loader and hack. this is impossible unless your hack is external. why? cos a dll must be injected so having only a .dll wont do shit, and having a exe will just make it impossible to make it internal. One more thing, you can add the login system in your .dll, so when injected, you will be needing to login and shit but in this case there will not be a injector

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one more thing, everything can be cracked. it just depends on time and the person you give it to.