Warning: Running or generating shellcode can be dangerous. Only work with binaries you own or have explicit permission to analyze. I provide a high-level, lawful-usage guide and reproducible steps for research, reverse engineering, or red-team testing in controlled environments.
Prerequisites
High-level approaches (pick one)
Step-by-step: Method A — Donut (fast, recommended)
Step-by-step: Method B — Manual packer that drops-and-executes (simpler, less stealthy)
Step-by-step: Method C — Manual in-memory PE loader (advanced, stealthy)
Recommended tooling and snippets
Safety, testing, and troubleshooting
Example minimal workflow (practical)
Further reading (tools to search)
If you want, I can:
Instead of writing the entire loader by hand (error-prone), you can:
Simpler manual method (using C):
// loader.c
unsigned char raw_pe[] = 0x4d, 0x5a, ... ; // Your EXE bytes
int main()
// ... implement mini-PE loader (complex)
Then compile loader.c to shellcode using msfvenom -p windows/x64/exec? Not ideal. Instead, compile it as an EXE, then run Donut on it – but that defeats the manual purpose.
Real-world manual example: The classic shellcode_exec from Metasploit's windows/exec is a hand-crafted PE-to-shellcode conversion, but for real tools, manual is rarely used today.
Converting an EXE to shellcode isn't a file format conversion; it's about taking the place of the Windows Loader.
You are embedding the logic required to parse the PE format, resolve dependencies, fix memory addresses, and execute the program—all within a self-contained blob of bytes. Understanding this process is fundamental for anyone looking to understand how modern malware operates "in-memory" and how security tools attempt to detect it.
Converting a standard .exe file into shellcode is not as simple as renaming the file or copying its bytes. A typical executable relies on the Operating System (OS) loader to handle complex tasks like memory allocation, resolving imports (DLLs), and base relocations. For an .exe to run as "shellcode," it must be converted into Position-Independent Code (PIC) that can execute from any memory address without these external OS dependencies. Common Tools for Conversion
Several specialized tools can automate the wrapping of an .exe into a shellcode-ready format:
Donut: This is the industry-standard tool for converting VBScript, JScript, EXE, DLL, and .NET assemblies into position-independent shellcode for x86 and x64 systems.
Pe2shc: A popular tool that makes a PE (Portable Executable) file act as a shellcode. It prepends a small stub that handles the necessary loading and relocation tasks at runtime.
exec2shell: A utility used to extract the .text (executable code) section of a PE or ELF file and output it as a raw binary or C-style array.
msfvenom: Part of the Metasploit framework, it can generate various payloads and encode existing executables into shellcode formats. Manual Method: Extracting the .text Section
If you only need the raw machine instructions from the executable code section, you can use a Python script with the pefile library to extract the .text segment.
import pefile import sys # Load the EXE file pe = pefile.PE(sys.argv[1]) # Function to grab executable code from the .text section def grab_executable_code(): ops = "" for section in pe.sections: # Looking for the primary executable section if b'.text' in section.Name: for item in bytearray(section.get_data()): # Format bytes as \x00 for shellcode strings ops += f"\\xitem:02x" return ops print(grab_executable_code()) Use code with caution. Copied to clipboard Key Technical Challenges
Embedding Shellcode in .text and .data section. | by Irfan Farooq
The Art of Converting Executable Files to Shellcode: A Comprehensive Guide
In the realm of computer security and malware analysis, shellcode is a term that is often thrown around. But what exactly is shellcode, and how is it used in the cybersecurity landscape? More importantly, how can you convert an executable file to shellcode? In this article, we'll delve into the world of shellcode, explore its applications, and provide a step-by-step guide on how to convert an executable file to shellcode.
What is Shellcode?
Shellcode is a type of machine code that is injected into a vulnerable process to execute a specific task. It is typically used by attackers to gain control over a system, bypass security mechanisms, and execute malicious code. Shellcode is usually written in assembly language and is designed to be small, efficient, and stealthy.
How is Shellcode Used?
Shellcode has a variety of uses in the cybersecurity landscape. Here are a few examples:
Converting Executable Files to Shellcode
Converting an executable file to shellcode involves disassembling the executable file, extracting the machine code, and formatting it into a shellcode-compatible format. Here's a step-by-step guide on how to do it:
Tools Needed
Step 1: Disassemble the Executable File
The first step is to disassemble the executable file using objdump. This will give us the machine code and the assembly code.
objdump -d -M intel ./example.exe
This command will disassemble the example.exe file and output the disassembly in Intel syntax.
Step 2: Extract the Machine Code
The next step is to extract the machine code from the disassembly. We can use xxd to convert the binary data to hexadecimal format.
xxd -p -c 100 ./example.exe
This command will output the hexadecimal representation of the machine code in 100-byte chunks.
Step 3: Format the Machine Code as Shellcode
The machine code needs to be formatted into a shellcode-compatible format. This involves converting the hexadecimal data into a byte array.
echo "\x01\x02\x03\x04" > shellcode.bin
This command will create a byte array with the hexadecimal values.
Step 4: Assemble the Shellcode
The final step is to assemble the shellcode using nasm.
nasm -f elf32 shellcode.bin -o shellcode.o
This command will assemble the shellcode into an ELF32 object file.
Step 5: Inject the Shellcode
The final step is to inject the shellcode into a vulnerable process. This can be done using various techniques such as buffer overflow exploitation or code injection.
Example Use Case
Let's say we have an executable file called example.exe that we want to convert to shellcode. We can follow the steps outlined above to convert it to shellcode.
objdump -d -M intel ./example.exe
xxd -p -c 100 ./example.exe
echo "\x01\x02\x03\x04" > shellcode.bin
nasm -f elf32 shellcode.bin -o shellcode.o
Once we have the shellcode, we can inject it into a vulnerable process to execute the malicious code.
Conclusion
Converting an executable file to shellcode is a complex process that requires a deep understanding of assembly language, machine code, and operating system internals. In this article, we provided a comprehensive guide on how to convert an executable file to shellcode. We also explored the uses of shellcode in the cybersecurity landscape and provided an example use case.
Recommendations
Additional Resources
By following this guide, you'll be able to convert executable files to shellcode and gain a deeper understanding of the complex world of shellcode. convert exe to shellcode
Converting an Executable (EXE) file into shellcode is a common technique used in red teaming and exploit development to execute programs in memory without dropping them on the disk. This process essentially wraps the PE (Portable Executable) file with a position-independent loader. Core Conversion Tools
The following tools are the industry standards for transforming compiled binaries into executable shellcode:
Donut: The most versatile tool for converting .NET Assemblies, EXE, and DLL files into position-independent shellcode.
Features: Supports x86 and x64, bypasses AMSI/WLDP, and offers compression (LZNT1, Xpress) to reduce payload size. Usage: donut.exe -f your_file.exe -o loader.bin.
Available on GitHub - TheWover/donut and as a Kali Linux package.
PE to Shellcode (pe2shc): Specifically designed to alter a PE file by adding a stub that allows it to be run as shellcode.
Benefit: It doesn't just hex-encode the file; it makes the PE itself executable as PIC (Position-Independent Code). Available on GitHub - hasherezade/pe_to_shellcode.
sRDI (Shellcode Reflective DLL Injection): Primarily for converting DLLs into shellcode that can be reflectively loaded. Available on GitHub - monoxgas/sRDI. Comparison of Methods Target Type Primary Use Case Output Format Donut .NET, EXE, DLL, JS, VBS Evasive in-memory execution binary (.bin), C, Python, Base64 pe2shc Windows PE (EXE/DLL) Direct conversion of PE to PIC binary (.bin) sRDI Windows DLL Stealthy reflective loading binary shellcode Advanced & Niche Options donut-shellcode | Kali Linux Tools
Converting a Windows executable (EXE) into shellcode is a fundamental technique in offensive security, primarily used to enable position-independent execution of complex payloads. Unlike standard executables, shellcode does not rely on the OS loader to resolve memory addresses or dependencies, making it ideal for process injection and fileless malware delivery. 1. Understanding Position-Independent Code (PIC)
Standard EXEs are typically compiled with hardcoded memory addresses and an Import Address Table (IAT) that requires the Windows Loader (ntdll!LdrLoadDll) to function. To convert an EXE to shellcode, the code must be transformed into Position-Independent Code (PIC). PIC can execute correctly regardless of its absolute address in memory by using relative addressing (RIP-relative in x64) and manually locating required functions in memory via the Process Environment Block (PEB). 2. Common Conversion Techniques
There are several established methods for performing this conversion:
Reflective DLL Injection: This technique involves adding a custom loader to a DLL that allows it to map itself into memory. Tools like the Metasploit Framework use this to inject payloads without touching the disk.
Donut: This is currently the industry standard for converting PE files (EXE, DLL, .NET) into position-independent shellcode. According to researchers at TheWover/donut, it works by creating a VBS/JS/EXE bootstrap that decrypts and loads the original payload directly into memory.
Manual PE Parsing: For custom implementations, developers write a "stub" in assembly or C. This stub parses the PE headers of the embedded EXE, allocates memory using VirtualAlloc, maps the sections, and resolves imports before jumping to the EntryPoint. 3. Implementation Workflow
A typical workflow for converting an EXE into a usable shellcode payload, as outlined by security labs like r19.io, follows these steps:
Generate the Payload: Create the target executable (e.g., a simple calc.exe launcher). Conversion: Use a tool like Donut to wrap the EXE. donut -i payload.exe -f 1 -o payload.bin Use code with caution. Copied to clipboard
Obfuscation: To bypass EDR/Antivirus, the resulting .bin file is often XOR-encoded or encrypted.
Formatting: Convert the binary data into a C-style array (using tools like xxd) for inclusion in a loader.
Execution: A loader is written to inject this shellcode into a target process (like explorer.exe) using APIs such as WriteProcessMemory and CreateRemoteThread. 4. Security Implications and EDR Bypass
The primary reason for EXE-to-shellcode conversion is evasion. Traditional antivirus software often scans files on the disk. By converting an EXE to shellcode, an attacker can: Execute the payload entirely in memory (Fileless). Bypass static signature-based detection.
Utilize Indirect Syscalls to hide the origin of memory allocation and thread creation from EDR hooks. 5. Conclusion
Converting an EXE to shellcode bridges the gap between high-level application development and low-level exploit delivery. While tools like Donut have automated the process, understanding the underlying PE structure and memory management is crucial for developing resilient and stealthy security tools.
Converting an executable (EXE) file into shellcode is a common requirement for security researchers and penetration testers. Shellcode is a payload of machine code that is executed by an exploit to perform a specific task, such as spawning a shell or establishing a reverse connection. Unlike standard executables, shellcode must be position-independent, meaning it can run regardless of where it is loaded in memory. Understanding the Conversion Process
A standard Windows EXE file relies on the Portable Executable (PE) format. This format includes headers, section tables, and import address tables (IAT) that tell the Windows Loader how to map the file into memory and resolve dependencies like kernel32.dll.
Shellcode does not have the luxury of a loader. When you convert an EXE to shellcode, you are essentially extracting the raw machine instructions and ensuring that any external functions the code needs are located manually at runtime, usually through techniques like parsing the Process Environment Block (PEB). Popular Methods to Convert EXE to Shellcode
There are several ways to approach this conversion, ranging from automated tools to manual extraction. 1. Using Donut
Donut is currently the industry standard for this task. It is a position-independent code generator that creates shellcode payloads from PE files, .NET assemblies, and even VBScript.
How it works: Donut wraps the EXE in a "loader" stub. When the shellcode executes, the stub decrypts the EXE, maps it into memory, and executes it. Warning: Running or generating shellcode can be dangerous
Key Feature: It supports both x64 and x86 architectures and can bypass many AMSI/ETW security checks. 2. Using PE2SHC
PE2SHC (PE to Shellcode) is a tool designed specifically to make a PE file "self-running" as shellcode.
How it works: It adds a small bootstrap at the beginning of the EXE. When you jump to the start of the file, this bootstrap relocates the rest of the PE structure in memory.
Benefit: It is very lightweight and preserves the original structure of the EXE, making it useful for researchers analyzing malware behavior. 3. Manual Extraction via Hex Editor
For very simple, self-contained programs written in C or Assembly, you can extract the .text section directly.
Process: Compile your code with all optimizations off and no external dependencies. Use a tool like objcopy or a Hex Editor to copy the bytes from the executable's code section.
Limitation: This only works if your code does not use any global variables or external DLL calls, as those addresses will be broken once moved. Key Challenges
Size Constraints: Shellcode is often injected into small memory buffers. Large EXEs may not fit.
Null Bytes: Many exploits fail if the shellcode contains null bytes (0x00), as they act as string terminators. You may need to encode your shellcode using tools like Shikata Ga Nai.
Architecture Mismatch: You must ensure the architecture (x86 vs x64) of your shellcode matches the target process you are injecting into. Step-by-Step Guide with Donut If you want the most reliable result, follow these steps: Prepare your EXE: Ensure it is a standalone executable.
Run Donut: Use the command line: donut.exe -i yourfile.exe -o payload.bin.
Test the Output: Use a simple C++ shellcode runner to load payload.bin into memory and execute it to verify functionality. If you'd like to dive deeper, let me know: Are you working with C++ or .NET? Do you need to bypass antivirus (AV) or EDR?
What is the target environment (Windows version, architecture)?
I can provide a specific code snippet for a shellcode runner or explain how to obfuscate the output.
Converting a standard Windows executable (.exe) directly into shellcode is not as simple as copying its raw bytes. Standard executables rely on the Windows OS loader to handle complex tasks like resolving imports (DLLs), performing relocations, and setting up memory sections. Shellcode, by definition, must be position-independent code (PIC)—meaning it can run anywhere in memory without these external setup steps. Here is how you can effectively bridge that gap. Method 1: Use a PE-to-Shellcode Converter (Recommended)
The most reliable way to convert an existing EXE is to use a "loader-in-shellcode" tool. These tools prepend a small, specialized loader (a "stub") to your executable that mimics the Windows OS loader's behavior at runtime.
Donut: One of the most popular tools for this purpose. It creates position-independent shellcode from VBScript, JScript, and standard PE files (EXE/DLL). It is highly flexible and supports both x86 and x64 architectures.
pe_to_shellcode: A tool by hasherezade that converts a PE file into a format that can be injected and run as shellcode while remaining a valid PE file.
InflativeLoading: A newer tool that dynamically converts unmanaged EXE/DLL files into PIC shellcode by prepending a shellcode stub to a dumped PE main module. Method 2: Manual Conversion via Assembly/C
If you are developing your own small tool and want it to be shellcode from the start, you can write it in a way that generates raw machine instructions directly.
Write Position-Independent Code: Avoid global variables and hardcoded memory addresses. Use the Instruction Pointer (RIP/EIP) for relative addressing.
Resolve APIs Dynamically: You cannot rely on an Import Address Table. Your code must manually find the base address of kernel32.dll (usually via the Process Environment Block or PEB) and then find the address of functions like GetProcAddress and LoadLibraryA.
Extract the Machine Code: After compiling your code (often into an Object file), use a tool like objdump or a hex editor to extract the raw bytes from the .text (code) section. Critical Technical Challenges
Imports & Dependencies: If your .exe depends on many third-party DLLs, the shellcode stub must be robust enough to find and load all of them in the target process.
Managed Code (.NET): Converting .NET executables (like Nanocore) is significantly harder because they require the Common Language Runtime (CLR) to be loaded first. Tools like Donut handle this by including a CLR header to bootstrap the environment.
Architecture Mismatch: You cannot run 64-bit shellcode in a 32-bit process (and vice versa) without complex "Heaven's Gate" techniques. Quick Comparison of Tools Donut General purpose, .NET, JS/VBS pe_to_shellcode Keeping the file valid while making it injectable InflativeLoading Unmanaged EXE/DLL with dynamic conversion
how can i created a shellcode.bin from .exe file #7 - GitHub