- NXcrypt is a polymorphic ‘python backdoors’ crypter written in python by Hadi Mene (h4d3s) . The output is fully undetectable .
- NXcrypt can inject malicious python file into a normal file with multi-threading system .
- Run it with superuser’s permissions .
- NXcrypt output is Fully undetectable
- sudo ./NXcrypt.py –file=backdoor.py –output=output_backdoor.py # encrypt backdoor.py and output file is output_backdoor.py
- sudo ./NXcrypt.py –file=shell.py # encrypt shell.py and default output file is backdoor.py but you can edit it in source code
- sudo ./NXcrypt.py –help # NXcrypt help
- sudo ./NXcrypt.py –backdoor-file=payload.py –file=test.py –output=hacked.py # inject payload.py with test.py into hacked.py with multi-threading system
How it work ?
- Encryption module :
- NXcrypt add some junkcode .
- NXcrypt use a python internal module ‘py_compile’ who compile the code into bytecode to a .pyc file .
- NXcrypt convert .pyc file into normal .py file .
- And in this way we can obfuscate the code
- The md5sum will change too
- Injection module :
- it inject a malicious python file into a normal file with multi-threading system .
Test with Virustotal
SHA256: e2acceb6158cf406669ab828d338982411a0e5c5876c2f2783e247b3e01c2163 File name: facebook.py Detection ratio: 2 / 54
SHA256: 362a4b19d53d1a8f2b91491b47dba28923dfec2d90784961c46213bdadc80add File name: facebook_encrypted.py Detection ratio: 0 / 55