PE-Packer – A Simple Windows X86 PE File Packer Written In C And Microsoft Assembly

PE-Packer is a simple packer for Windows PE files. The new PE file after packing can obstruct the process of reverse engineering.

It will do the following things when packing a PE file:

• Transforming the original import table.
• Encrypting sections.
• Clearing section names.
• Installing the shell-entry.

When running a packed PE file, the shell-entry will decrypt and load the original program as follows:

• Decrypting sections.
• Initializing the original import table.
• Relocation.

Before packing, using some disassembly tools can disassemble the executable file to analyze the code, such as IDA Pro.

• Disassembling the code.

  

• Searching constant strings.

  

• Analyzing the import table.

  

After packing, the reverse analysis will be obstructed.

• Disassembling the code.

  

• Searching constant strings.

  

• Analyzing the import table.

  

Warning

This project is just a demo for beginners to study Windows PE Format and Assembly Language. It still has some compatibility problems and bugs that cannot be used in practice.

Getting Started

Prerequisites

The project must configure on/for Windows 32-bit and can only process 32-bit .exe programs now.

• Install MASM32.
• Install MinGW-w64, select i686 architecture.
• Install CMake.
• Set the PATH environment variables of these three tools.

Building

> mkdir -p build
> cd build
> cmake .. -D CMAKE_C_COMPILER=gcc -G "MinGW Makefiles"
> cmake --build .

Or run the build.ps1 file directly:

> .build.ps1

Usage

To pack a program, you must specify its input name and the output name.

PE-Packer <input-file> <output-file>

For example:

PE-Packer hello.exe hello-pack.exe

Documents

You can use Doxygen to generate the document.

In order to avoid scanning .md files, you must add *.md to the EXCLUDE_PATTERNS configuration option.

EXCLUDE_PATTERNS = *.md

This option is in “Expert” -> “Input” page.

References

《加密与解密（第3版）》段钢

PE Format – Windows Dev Center

Contact

GitHub: https://github.com/czs108/

E-Mail: [email protected]

WeChat: chenzs108