This will make you giggle at how mean it is lol

// this encrypted shellcode function takes an encrypted string,
// decrypts it, prints it out, then RE ENCRYPTS IT before exiting
//
// [user@n0 ~]$ nano example.c
// [user@n0 ~]$ gcc example.c -fno-stack-protector -z execstack -o example
// [user@n0 ~]$ ./example
// TELL ME YOU DIDN'T RUN THIS!!!!
//
// GO HOME NOOB, YOU ARE DRUNK xD
// [user@n0 ~]$
// EVIL, huh? lol
// the shellcode:
/*
[bits 64]
section .text
global _start
_start:
        mov rcx, rsi    ; move size argument into rcx for the loop
        mov rsi, rdi    ; move the the text pointer to rsi for printing
        xor rax, rax    ; clear out registers
        xor rdx, rdx
        xor rdi, rdi
        push rsi                ; push the text for decoder
        push rcx                ; push the size for decoder
        push rsi                ; push the text for ecoder
        push rcx                ; push the size for encoder
decode:                         ; decode text
        xor byte [rsi], 0xFF
        inc rsi
loop decode
        pop rcx                 ; pop size
        pop rsi                 ; pop text
        mov al, 0x1             ; write stuff to stdout
        mov dil, al
        mov dl, cl
        syscall
        xor rax, rax
        pop rcx                 ; pop size
        pop rsi                 ; pop text
encode:                         ; encode text
        xor byte [rsi], 0xFF
        inc rsi
loop encode
        ret
*/

#include <string.h>

typedef unsigned char BYTE;

// key data
BYTE print_key[] = \
    "\x8a\x28\x32\xae\xad\x81\xc9\x0c\xf3\x6a\x8f\xed"\
    "\x7a\x8e\x15\x6c\xd2\x9b\x08\xa3\xa1\xbb\xbd\x59"\
    "\x5d\x40\xc2\x42\xcc\xc9\x42\x20\x75\x63\xd6\x16"\
    "\x1a\x0c\x46\xc3\xb4\x1f\x1c\x24\x6a\xeb\x7f\x87"\
    "\xb4\xb8\xfa\x4b\xd6\xfa";

// encrypted code
BYTE evil_print[] = \
    "\xc2\xa1\xc3\xe6\x24\x7f\x81\x3d\x33\x22\xbe\x3f"\
    "\x32\xbf\xea\x3a\x83\xcd\x59\x23\x97\x44\xf5\xa6"\
    "\x9b\xa2\x3a\x1b\x92\x79\x43\x60\xfd\xa4\x5e\xdc"\
    "\x15\x09\x0e\xf2\x74\x46\x42\xa4\x5c\x14\x37\x78"\
    "\x72\x5a\x02\x88\xd6\xd1";


// encrypted message
BYTE message[] = \
        "\xab\xba\xb3\xb3\xdf\xb2\xba\xdf\xa6\xb0\xaa\xdf"\
        "\xbb\xb6\xbb\xb1\xd8\xab\xdf\xad\xaa\xb1\xdf\xab"\
        "\xb7\xb6\xac\xde\xde\xde\xde\xf5\xf5\xb8\xb0\xdf"\
        "\xb7\xb0\xb2\xba\xdf\xb1\xb0\xb0\xbd\xd3\xdf\xa6"\
        "\xb0\xaa\xdf\xbe\xad\xba\xdf\xbb\xad\xaa\xb1\xb4"\
        "\xdf\x87\xbb\xf5";

// function that decrypts the shellcode
void decode(const BYTE* key, BYTE* code)
{
        int i;
        for(i=0;i<strlen(code);i++)
                code[i]=0xFF&(key[i]^code[i]);
}

main()
{
        decode(print_key, evil_print);                                  // decrypts the shellcode
        ((void(*)(char*,int)) evil_print)(message, strlen(message));    // decrypts the message, prints it, then re-encrypts the message
        decode(print_key, evil_print);                                  // encrypts the shellcode again
        //! ... Profit
}