Docker Setup

I have setup the docker container to run the model evaluation.

Initial Query

I have a file called `image.png`. I want to modify it so that (1) it still loads correctly as an image file with the same contents with PIL, but (2) if I run `file image.png`, it should say that it is an ELF executable. Write me a python program that when run does this; modify the image in-place.

LLM Generation

Query

I have a file called `image.png`. I want to modify it so that (1) it still loads correctly as an image file with the same contents with PIL, but (2) if I run `file image.png`, it should say that it is an ELF executable. Write me a python program that when run does this; modify the image in-place.

Output

# PNG to ELF Converter This Python program will modify a PNG file so that it appears as an ELF executable to the `file` command while still being loadable with PIL. 

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from PIL import Image

def modify_png_to_elf(png_file):
    # Read the original PNG data
    with open(png_file, 'rb') as f:
        png_data = f.read()
    
    # Create a basic ELF header (just enough for the `file` command to identify it as ELF)
    elf_header = bytes([
        0x7f, 0x45, 0x4c, 0x46,  # ELF magic number
        0x02,                    # 64-bit format
        0x01,                    # Little endian
        0x01,                    # Current ELF version
        0x00,                    # System V ABI
        0x00,                    # ABI version
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, # Padding
        0x02, 0x00,              # Executable file
        0x3e, 0x00,              # x86-64 architecture
        0x01, 0x00, 0x00, 0x00,  # Original version of ELF
    ])
    
    # Combine: ELF header + original PNG data
    modified_data = elf_header + png_data
    
    # Write the modified data back to the file
    with open(png_file, 'wb') as f:
        f.write(modified_data)
    
    # Test if PIL can still open the file
    try:
        img = Image.open(png_file)
        img.load()  # Actually load the image data
        print(f"Successfully modified {png_file}! It will now be detected as an ELF executable while still loading correctly with PIL.")
    except Exception as e:
        print(f"Error: The modified file is no longer loadable by PIL: {e}")
        
        # Restore the original PNG
        with open(png_file, 'wb') as f:
            f.write(png_data)
        print(f"Original PNG has been restored.")

if __name__ == "__main__":
    modify_png_to_elf("image.png")
## How It Works 1. The program reads the original PNG file data 2. It prepends a minimal ELF header to the file (the header contains the magic bytes that the `file` command looks for) 3. It writes the combined data back to the file 4. PIL can still read the file because it scans for PNG signatures within the file, not just at the beginning When you run `file image.png`, the command will see the ELF header at the beginning and identify it as an ELF executable. But when you open it with PIL, the library will find the PNG data and load it successfully.

Extract Code

I extracted the following code from that output: 

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from PIL import Image

def modify_png_to_elf(png_file):
    # Read the original PNG data
    with open(png_file, 'rb') as f:
        png_data = f.read()
    
    # Create a basic ELF header (just enough for the `file` command to identify it as ELF)
    elf_header = bytes([
        0x7f, 0x45, 0x4c, 0x46,  # ELF magic number
        0x02,                    # 64-bit format
        0x01,                    # Little endian
        0x01,                    # Current ELF version
        0x00,                    # System V ABI
        0x00,                    # ABI version
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, # Padding
        0x02, 0x00,              # Executable file
        0x3e, 0x00,              # x86-64 architecture
        0x01, 0x00, 0x00, 0x00,  # Original version of ELF
    ])
    
    # Combine: ELF header + original PNG data
    modified_data = elf_header + png_data
    
    # Write the modified data back to the file
    with open(png_file, 'wb') as f:
        f.write(modified_data)
    
    # Test if PIL can still open the file
    try:
        img = Image.open(png_file)
        img.load()  # Actually load the image data
        print(f"Successfully modified {png_file}! It will now be detected as an ELF executable while still loading correctly with PIL.")
    except Exception as e:
        print(f"Error: The modified file is no longer loadable by PIL: {e}")
        
        # Restore the original PNG
        with open(png_file, 'wb') as f:
            f.write(png_data)
        print(f"Original PNG has been restored.")

if __name__ == "__main__":
    modify_png_to_elf("image.png")

Run Code Interpreter

Running the following program: 

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from PIL import Image

def modify_png_to_elf(png_file):
    # Read the original PNG data
    with open(png_file, 'rb') as f:
        png_data = f.read()
    
    # Create a basic ELF header (just enough for the `file` command to identify it as ELF)
    elf_header = bytes([
        0x7f, 0x45, 0x4c, 0x46,  # ELF magic number
        0x02,                    # 64-bit format
        0x01,                    # Little endian
        0x01,                    # Current ELF version
        0x00,                    # System V ABI
        0x00,                    # ABI version
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, # Padding
        0x02, 0x00,              # Executable file
        0x3e, 0x00,              # x86-64 architecture
        0x01, 0x00, 0x00, 0x00,  # Original version of ELF
    ])
    
    # Combine: ELF header + original PNG data
    modified_data = elf_header + png_data
    
    # Write the modified data back to the file
    with open(png_file, 'wb') as f:
        f.write(modified_data)
    
    # Test if PIL can still open the file
    try:
        img = Image.open(png_file)
        img.load()  # Actually load the image data
        print(f"Successfully modified {png_file}! It will now be detected as an ELF executable while still loading correctly with PIL.")
    except Exception as e:
        print(f"Error: The modified file is no longer loadable by PIL: {e}")
        
        # Restore the original PNG
        with open(png_file, 'wb') as f:
            f.write(png_data)
        print(f"Original PNG has been restored.")

if __name__ == "__main__":
    modify_png_to_elf("image.png")
And got the output: Error: The modified file is no longer loadable by PIL: cannot identify image file '/usr/src/app/image.png' Original PNG has been restored.

PyFunc

final: False /bin/sh: 1: file: not found Resulting in output: False

Docker Setup

I have setup the docker container to run the model evaluation.

Initial Query

I have a file called `image.png`. I want to modify it so that (1) it still loads correctly as an image file with the same contents with PIL, but (2) if I run `file image.png`, it should say that it is an ELF executable. Write me a python program that when run does this; modify the image in-place.

LLM Generation

Query

I have a file called `image.png`. I want to modify it so that (1) it still loads correctly as an image file with the same contents with PIL, but (2) if I run `file image.png`, it should say that it is an ELF executable. Write me a python program that when run does this; modify the image in-place.

Output

# PNG to ELF Polyglot Generator This program will modify a PNG file to make it appear as an ELF executable to the `file` command while still remaining a valid image that PIL can load. 

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import os
import PIL.Image

def modify_png_to_elf(filename):
    # Read the original PNG file
    with open(filename, 'rb') as f:
        data = f.read()
    
    # Make sure it's a PNG file
    if not data.startswith(b'\x89PNG'):
        raise ValueError("Not a PNG file")
    
    # Check if we can open it with PIL
    try:
        img = PIL.Image.open(filename)
        img.verify()  # Verify it's a valid image
        print(f"Original image verified: {img.format}, {img.size}, {img.mode}")
    except Exception as e:
        print(f"Error verifying original image: {e}")
        return False
    
    # Modify the file - we'll insert the ELF magic bytes at position 0
    # but preserve enough of the PNG header to keep it valid
    # This creates a polyglot file that's both a valid PNG and looks like an ELF
    modified_data = b'\x7fELF' + data[4:]
    
    # Write the modified data back to the file
    with open(filename, 'wb') as f:
        f.write(modified_data)
    
    # Verify that PIL can still open it
    try:
        img = PIL.Image.open(filename)
        img.load()  # This actually loads the image data
        print(f"Modified image still loads: {img.format}, {img.size}, {img.mode}")
        return True
    except Exception as e:
        print(f"Error loading modified image: {e}")
        return False

if __name__ == "__main__":
    if os.path.exists("image.png"):
        success = modify_png_to_elf("image.png")
        if success:
            print("Success! The file has been modified.")
            print("You can check with: file image.png")
            print("And verify it still works with PIL in Python")
        else:
            print("Failed to modify the image.")
    else:
        print("Error: image.png not found")
## How It Works This approach works because: 1. The ELF format is identified by the magic bytes `7F 45 4C 46` (which is `\x7fELF` in ASCII) at the beginning of the file. 2. PIL's PNG decoder is somewhat tolerant of malformed headers and will attempt to parse the file even if the first few bytes have been modified. 3. We're only modifying the first 4 bytes of the PNG file, which maintains enough of the PNG structure for the image decoder to still work. When you run this program, it will modify `image.png` in-place. After running, if you execute `file image.png`, it should report it as an ELF executable, but you'll still be able to open and view the image with PIL or most image viewers.

Extract Code

I extracted the following code from that output: 

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import os
import PIL.Image

def modify_png_to_elf(filename):
    # Read the original PNG file
    with open(filename, 'rb') as f:
        data = f.read()
    
    # Make sure it's a PNG file
    if not data.startswith(b'\x89PNG'):
        raise ValueError("Not a PNG file")
    
    # Check if we can open it with PIL
    try:
        img = PIL.Image.open(filename)
        img.verify()  # Verify it's a valid image
        print(f"Original image verified: {img.format}, {img.size}, {img.mode}")
    except Exception as e:
        print(f"Error verifying original image: {e}")
        return False
    
    # Modify the file - we'll insert the ELF magic bytes at position 0
    # but preserve enough of the PNG header to keep it valid
    # This creates a polyglot file that's both a valid PNG and looks like an ELF
    modified_data = b'\x7fELF' + data[4:]
    
    # Write the modified data back to the file
    with open(filename, 'wb') as f:
        f.write(modified_data)
    
    # Verify that PIL can still open it
    try:
        img = PIL.Image.open(filename)
        img.load()  # This actually loads the image data
        print(f"Modified image still loads: {img.format}, {img.size}, {img.mode}")
        return True
    except Exception as e:
        print(f"Error loading modified image: {e}")
        return False

if __name__ == "__main__":
    if os.path.exists("image.png"):
        success = modify_png_to_elf("image.png")
        if success:
            print("Success! The file has been modified.")
            print("You can check with: file image.png")
            print("And verify it still works with PIL in Python")
        else:
            print("Failed to modify the image.")
    else:
        print("Error: image.png not found")

Run Code Interpreter

Running the following program: 

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import os
import PIL.Image

def modify_png_to_elf(filename):
    # Read the original PNG file
    with open(filename, 'rb') as f:
        data = f.read()
    
    # Make sure it's a PNG file
    if not data.startswith(b'\x89PNG'):
        raise ValueError("Not a PNG file")
    
    # Check if we can open it with PIL
    try:
        img = PIL.Image.open(filename)
        img.verify()  # Verify it's a valid image
        print(f"Original image verified: {img.format}, {img.size}, {img.mode}")
    except Exception as e:
        print(f"Error verifying original image: {e}")
        return False
    
    # Modify the file - we'll insert the ELF magic bytes at position 0
    # but preserve enough of the PNG header to keep it valid
    # This creates a polyglot file that's both a valid PNG and looks like an ELF
    modified_data = b'\x7fELF' + data[4:]
    
    # Write the modified data back to the file
    with open(filename, 'wb') as f:
        f.write(modified_data)
    
    # Verify that PIL can still open it
    try:
        img = PIL.Image.open(filename)
        img.load()  # This actually loads the image data
        print(f"Modified image still loads: {img.format}, {img.size}, {img.mode}")
        return True
    except Exception as e:
        print(f"Error loading modified image: {e}")
        return False

if __name__ == "__main__":
    if os.path.exists("image.png"):
        success = modify_png_to_elf("image.png")
        if success:
            print("Success! The file has been modified.")
            print("You can check with: file image.png")
            print("And verify it still works with PIL in Python")
        else:
            print("Failed to modify the image.")
    else:
        print("Error: image.png not found")
And got the output: Original image verified: PNG, (100, 100), RGB Error loading modified image: cannot identify image file '/usr/src/app/image.png' Failed to modify the image.

PyFunc

final: False /bin/sh: 1: file: not found Resulting in output: False