coding question

hi people
i dont know if i'm right here, but asking costs no money.

so i have coding a trojan in c++, this trojan sniffs for packets whichs looks like password-packets. then it reads the passwords and encrypt the data and send them to a remote host, where another tool decryt them and save them in a text file.

but my problem is in the trojan body you can read(with an hex-editor) the encyption key and the remote host address in plain text.

are there any nice tools out there, which can encrypt the trojan file ? at the moment i use upx and then the upx scrambler, but this is not really secure.

please help me