NXcrypt : Python Backdoor

Written by Mubassir patel


  • NXcrypt is a polymorphic ‘python backdoors’ crypter written in python by Hadi Mene (h4d3s) . The output is fully undetectable .
  • This tool can inject malicious python file into a normal file with multi-threading system .
  • Run it with superuser’s permissions .
  • This tool’s output is Fully undetectable .

Backdooring Module :


Encryption Module


Usage :

  • sudo ./ – – # encrypt and output file is
  • sudo ./ – # encrypt and default output file is but you can edit it in source code
  • sudo ./ –help # NXcrypt help
  • sudo ./ – – – # inject with into with multi-threading system

How it work ?

  • Encryption module :
  • This tool add some junkcode .
  • This is use a python internal module ‘py_compile’ who compile the code into bytecode to a .pyc file .
  • This tool can be convert .pyc file into normal .py file .
  • And in this way we can obfuscate the code
  • The md5sum will change too
  • Injection module :
  • NXCrypt inject a malicious python file into a normal file with multi-threading system .

Test with Virustotal

Before :

SHA256: e2acceb6158cf406669ab828d338982411a0e5c5876c2f2783e247b3e01c2163 File name: Detection ratio: 2 / 54

After :

SHA256: 362a4b19d53d1a8f2b91491b47dba28923dfec2d90784961c46213bdadc80add File name: Detection ratio: 0 / 55

About the author

Mubassir patel

Mubassir is a founder and developer of this site. He is a computer science engineer. He has a very deep interest in ethical hacking, penetration testing, website development and including all technology topic.

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