ProcJack is a code injection toolkit with which you can inject your code into a running process. Injection is achieved by the same technique as ReflectiveDLLInjection does, i.e. the combination of CreateRemoteThread and VirtualAllocEx.

The key difference of ProcJack from other injection toolkits are:

• You can invoke a DLL-exported function in the target process (not DllMain)
• You can pass a string into your injected code through the command line arguments
• Injection footprint can be completely cleaned up i.e. unloading the injected module and freeing the allocated pages

The supported architecture of a target process is Native x86/x64 and WoW64. No ARM support. No Linux support.

This project consists of multiple modules.

• pj.exe is a main injector program. You run this executable to inject a DLL (or a flat binary file) into a process.

• spy.dll is a sample injectee DLL which can be injected by pj.exe. The injected code prints some information on debugger console (See the "How to play" section below). This is a ProcJack version of "Hello world".

• expeb.exe is used to design a shellcode in pj.exe. This is for development purpose only.

• t.exe is a test program.

• clove.dll is an injectee DLL to run Non-invasive (in-memory) Instrumentation, with which you can instrument a running process without modifying or rebuilding its source code. For more details, please check out Intro.pdf.

1. Install Visual Studio Community
   https://www.visualstudio.com/downloads/

2. Download The Netwide Assembler
   http://www.nasm.us/

3. Clone and build Google Test
   https://github.com/google/googletest

4. Clone and build Microsoft Detours
   https://github.com/Microsoft/Detours

5. Update the following labels in common.mak

DETOUR_DIR=<your local repo of Microsoft Detours repository>
GTEST_SRC_DIR=<your local repo of Google Test>
GTEST_BUILD_DIR=<your CMake build directory of Google Test>
NASM=<the path to nasm.exe>

6. Build
   Open "Native Tools Command Prompt" of Visual Studio and run NMAKE under the root of this repository. Binaries will be generated under bin/[x86|amd64].

Let's inject the sample spy.dll!

1. Identify PID of a target process. In this example, let's use notepad.exe below: PID=12884.

G:\10_Git\procjack>tasklist | find "notepad"
notepad.exe                  12884 Console                    1     11,996 K

2. Because the sample function of spy.dll prints a debug message via OutputDebugString, you need to attach your favorite debugger to the target process to see a visible result.

3. Run the following command. The command says "Load spy.dll, and invoke a function of ordinal number 100 in the process of PID 12884". The string "Hello!" is an optional parameter. If you pass multiple (space-delimited) strings from the command line, you can get them as a null-delimited string in the function to be invoked (See the next section).

> G:\10_Git\procjack> bin\amd64\pj.exe 12884 bin\amd64\spy.dll?100 Hello!
Hijacking: PID=3254 (WIN64) TID=25d8 VM=0000028CC90D0000

VM=0000028CC90D0000 in the output above means the injector remotely allocated a region at 0000028CC90D0000 in the target in order to store code and data. This address would be helpful when you need to debug the target process for some reason.

4. On the debugger console attached to the target, you'll see an output like this. Injection done!

ModLoad: 00007ffe`54780000 00007ffe`54805000   G:\10_Git\procjack\bin\amd64\spy.dll
Injection Package:
 Page = 0000028CC90D0000
 DLL  = G:\10_Git\procjack\bin\amd64\spy.dll
 PEB  = 0000009D2E3D6000
 Args = Hello!

5. After the invoked function is finished, everything is cleaned up. You can make sure spy.load is unloaded and the address 0000028CC90D0000 is no longer available.

0:001>  lm m spy
start             end                 module name
0:001> db 0000028CC90D0000 l10
0000028c`c90d0000  ?? ?? ?? ?? ?? ?? ?? ??-?? ?? ?? ?? ?? ?? ?? ??  ????????????????

The injector pj.exe invokes an exported function by specifying an ordinal number in a target process. There is no special restriction. What you need to do is to write a DLL and to export a function with an ordinal number.

Exporting Functions from a DLL by Ordinal Rather Than by Name | Microsoft Docs
https://docs.microsoft.com/en-us/cpp/build/exporting-functions-from-a-dll-by-ordinal-rather-than-by-name

The function can receive one pointer pointing to meta information, that is represented as the structure Package defined as follows. For example, you can access the optional arguments through Package::args.

struct Package {
  union NonWritable {
    struct {
      uint8_t shellcode[SHELLCODE_CAPACITY];
      wchar_t dllpath[260];
      char args[1];
    };
    uint8_t dummy[4096];
  } nw;

  HybridPointer<PEB> peb;
  HybridPointer<void> kernel32;
  HybridPointer<void*(WINAPI)(void*)> xxxLoadLibrary;
  HybridPointer<uint32_t(WINAPI)(void*)> xxxFreeLibrary;
  HybridPointer<void*(WINAPI)(void*, void*)> xxxGetProcAddress;
};