Unfortunately, there is no way to stop hackers. There is just more ways to try to prevent them from figuring out how your game is coded, and how it reads.
To add to that, you are using TFS. Its aleady an open sorce, and if you get the wrong files, you could end up with keyloggers, and other things to tell them you're information.
I suggest making sure you have a good distro, then reframe from using premade AAC's. Meaning make you're own. Then make sure you're database is nice and secure.
Also, I wouldn't use the servers pre-made admin. Its just another link in the server to get hacked from.
There could be a automatic admin on every server that elf, ect. put on and no one would know. Unless you checked the engine, good luck getting through all that code.