Converting an EXE file to shellcode is not as simple as copying its raw bytes. A standard EXE (Portable Executable) file contains headers, section tables, and external dependencies that require an operating system loader to function. Shellcode, by contrast, must be Position Independent Code (PIC) —it must be able to run from any memory address without relying on fixed offsets or pre-loaded libraries. Core Challenges The OS Loader: Standard EXEs rely on the OS to set up memory sections and resolve imports (like DLLs). Hardcoded Addresses: Most compiled EXEs use absolute memory addresses that break if the code is moved. External Dependencies: Functions like printf or WinExec must be manually located by the shellcode at runtime. Methods for Conversion 1. Using Automated Tools (Recommended) The most reliable way to convert an existing EXE into shellcode is using tools that wrap the EXE in a "loader stub." This stub acts as a mini-OS loader to handle memory allocation and dependency resolution. Donut : A popular tool that creates position-independent shellcode payloads from Windows VBScript, JScript, EXE, DLL files, and .NET assemblies. Pe2sh : Converts a standard PE file into shellcode by prepending a custom loader. Exe2shell : A utility specifically designed to extract and convert executable segments into usable shellcode. 2. Manual C/C++ Extraction You can write code specifically designed to be extracted as shellcode. Write PIC Code: Use only local variables and avoid global strings. Manually locate functions using the Process Environment Block (PEB) to find kernel32.dll and GetProcAddress . Extract the .text Section: Once compiled, use a debugger or tools like objcopy to dump the raw machine instructions from the .text section (the code segment). Visual Studio Disassembly: Compile your function, set a breakpoint, and use the "Disassembly" view to copy the raw hex bytes. 3. Assembly Language (The Traditional Way) For absolute control and the smallest size, shellcode is often written directly in Assembly. [IT432] Class 12: Shellcode A shellcode is just the assembly version of the code calling execve("/bin/sh", ...) as above. United States Naval Academy How to - Convert Quasar RAT into Shellcode with Donut.exe
To convert a Portable Executable (PE/EXE) to shellcode, you must transform the machine code into a position-independent format that can execute regardless of where it is loaded in memory. Quick Methods to Convert EXE to Shellcode The most effective way to handle this conversion is through specialized tools that wrap the original executable with a custom loader. Donut (Highly Recommended) : This is the industry standard for creating position-independent shellcode payloads from .NET assemblies, PEs, and DLLs. donut.exe -i to generate a loader.bin file containing the shellcode. : Available on TheWover's Donut GitHub PE to Shellcode (pe2shc) : Specifically designed to convert a 32-bit or 64-bit EXE into a shellcode blob that remains a valid PE but can be executed like shellcode. pe2shc.exe : Available on hasherezade's GitHub : A simpler Python/Rust-based utility for basic conversions. python3 exe2shell.py : Available on daVinci13's GitHub Report: Challenges & Requirements Converting a standard EXE to shellcode is not as simple as copying bytes; the resulting code must satisfy several technical conditions to run successfully: Stack Overflow Generating Shellcode from an exe? [closed] - Stack Overflow
Converting EXE to Shellcode: A Step-by-Step Guide Introduction Shellcode is a type of machine code that is injected into a computer's memory to execute a specific task. It's often used in exploit development, malware analysis, and reverse engineering. In this guide, we'll walk you through the process of converting an EXE file to shellcode. Prerequisites
Operating System: Windows (for this example, we'll use Windows 10) Toolchain: convert exe to shellcode
objdump (part of the binutils package) nasm (Netwide Assembler) msvc (Microsoft Visual C++ compiler)
Step 1: Obtain the EXE File For this example, let's assume you have a simple EXE file called example.exe . You can create one using a basic C program: #include <stdio.h>
int main() { printf("Hello, World!\n"); return 0; } Converting an EXE file to shellcode is not
Compile it using: gcc -o example.exe example.c
Step 2: Extract the Binary Data Use objdump to extract the binary data from the EXE file: objdump -d example.exe -M intel -S
This will disassemble the EXE file and display the binary data. You can redirect the output to a file: objdump -d example.exe -M intel -S > example.disasm Core Challenges The OS Loader: Standard EXEs rely
Step 3: Convert to Shellcode To convert the EXE file to shellcode, you'll need to:
Remove headers and metadata: EXE files contain headers, section tables, and other metadata that aren't needed for shellcode. You can use a tool like dumpbin (part of the Microsoft Visual Studio toolchain) to extract the raw binary data: