pwncat is a post-exploitation platform for Linux targets. It started out as a wrapper around basic bind and reverse shells and has grown from there. It streamlines common red team operations while staging code from your attacker machine, not the target.
pwncat intercepts the raw communication with a remote shell and allows the user to perform automated actions on the remote host including enumeration, persistence installation and even privilege escalation.
After receiving a connection, pwncat will setup some common configurations for working with remote shells.
- Disable history in the remote shell
- Normalize shell prompt
- Locate useful binaries (using
which
) - Attempt to spawn a pseudoterminal (pty) for a full interactive session
pwncat
knows how to spawn pty's with a few different methods and will
cross-reference the methods with the executables previously enumerated. After
spawning a pty, it will setup the controlling terminal in raw mode, so you can
interact in a similar fashion to ssh
.
pwncat
will also synchronize the remote pty settings (such as rows, columns,
TERM
environment variable) with your local settings to ensure the shell
behaves correctly with interactive applications such as vim
or nano
.
John Hammond and I presented pwncat
at GRIMMCon. Our presentation, which
can be found on YouTube here.
This video demonstrates an early version of the API and interface. Please
refer to the documentation for up to date usage and API documentation!
pwncat documentation is being built out on Read the Docs. Head there for the latest usage and development documentation!
Recently, the architecture of the pwncat framework was redesigned to
encorporate a generic "module" structure. All functionality is now
implemented as modules. This includes enumeration, persistence and
privilege escalation. Interacting with modules is similar to most other
post-exploitation platforms. You can utilize the familiar run
, search
and info
commands and enter module contexts with the use
command.
Refer to the documentation for more information.
pwncat
only depends on a working Python development environment. In order
to install some of the packages required with pip
, you will likely need
your distribution's "Python Development" package. On Debian based systems,
this is python-dev
. For Arch, the development files are shipped with the
main Python repository. For Enterprise Linux, the package is named
python-devel
.
pwncat
is configured as a standard python package with distutils
. You
can install pwncat
directly from GitHub with:
pip install git+https://github.com/calebstewart/pwncat.git
Or, you can install after cloning the repository with:
python setup.py install
pwncat
depends on a custom fork of paramiko
. I'm working on removing
this dependency, but sadly my fork of paramiko was never merged upstream
so currently that's where we stand. If pip
decided not to install the
fork (which happens sometimes), then you will get a message from pwncat
stating that you have the wrong version with instructions for correcting
the dependency failure.
It is recommended to install pwncat from a virtual environment.
python3 -m venv pwncat-env
source pwncat-env/bin/activate
python setup.py install
If you would like to develop custom privilege escalation or persistence
modules, we recommend you use the develop
target vice the install
target
for setup.py
. This allows changes to the local repository to immediately
be observed with your installed package.
The setup script will install three binaries. They are all identical, but
provide convenience aliases for pwncat. The three binaries are: pwncat
,
pc
and pcat
.
The command line parameters for pwncat attempt to be flexible and accept a variety of common connection syntax. Specifically, it will try to accept common netcat and ssh like syntax. The following are all valid:
# Connect to a bind shell
pwncat connect://10.10.10.10:4444
pwncat 10.10.10.10:4444
pwncat 10.10.10.10 4444
# Listen for reverse shell
pwncat bind://0.0.0.0:4444
pwncat 0.0.0.0:4444
pwncat :4444
pwncat -lp 4444
# Connect via ssh
pwncat ssh://user:password@10.10.10.10
pwncat user@10.10.10.10
pwncat user:password@10.10.10.10
pwncat -i id_rsa user@10.10.10.10
# SSH w/ non-standard port
pwncat -p 2222 user@10.10.10.10
pwncat user@10.10.10.10:2222
# Reconnect utilizing installed persistence
# If reconnection failes and no protocol is specified,
# SSH is used as a fallback.
pwncat reconnect://user@10.10.10.10
pwncat reconnect://user@c228fc49e515628a0c13bdc4759a12bf
pwncat user@10.10.10.10
pwncat c228fc49e515628a0c13bdc4759a12bf
pwncat 10.10.10.10
For more information on the syntax and argument handling, see the
help information with pwncat --help
or visit the documentation.
When connecting to a host with SSH, paramiko
is used to connect. Due to
paramiko not implementing the full socket interface, I forked paramiko and
implemented the features to make it compatible with a built-in socket. I
submitted a pull request with paramiko
. The pull request was accepted but
has still not been merged. As a result, the setup.py
script references
my custom fork of paramiko. Some users have had issues where python does
not install the custom fork and instead installs standard paramiko. In this
case, you will get an error telling you to install the custom fork of
paramiko. I'm working on fixing the setup script to ensure the correct version
is installed and in the long run would like to remove this dependency eventually.
In the meantime, if the fix recommended by pwncat does not work, please
comment on issue #60 for help.
The recommended installation method is a Python virtual environment. This
provides the easiest day-to-day usage of pwncat
. However, there has been
interest in using pwncat
from a docker image, so I have provided a
Dockerfile which provides a working pwncat
installation. To build the image
use:
docker build -t pwncat .
This will build the pwncat
docker image with the tag "pwncat". The working
directory within the container is /work
. The entrypoint for the container
is the pwncat
binary. It can be used like so:
# Connect to a bind shell at 10.0.0.1:4444
docker run -v "/some/directory":/work -t pwncat 10.0.0.1 4444
In this example, only the files in /some/directory
are exposed to the container.
Obviously, for upload/download, the container will only be able to see the files
exposed through any mounted directories.
pwncat
provides two main features. At it's core, it's goal is to automatically
setup a remote PseudoTerminal (pty) which allows interaction with the remote
host much like a full SSH session. When operating in a pty, you can use common
features of your remote shell such as history, line editing, and graphical
terminal applications.
The other half of pwncat
is a framework which utilizes your remote shell to
perform automated enumeration, persistence and privilege escalation tasks. The
local pwncat
prompt provides a number of useful features for standard
penetration tests including:
- File upload and download
- Automated privilege escalation enumeration
- Automated privielge escalation execution
- Automated persistence installation/removal
- Automated tracking of modified/created files
pwncat
also offers the ability to revert these remote "tampers" automatically
The underlying framework for interacting with the remote host aims to abstract away the underlying shell and connection method as much as possible, allowing commands and plugins to interact seamlessly with the remote host.
You can learn more about interacting with pwncat
and about the underlying framework
in the documentation. If you have an idea for a new privilege escalation method
or persistence method, please take a look at the API documentation specifically.
Pull requests are welcome!
pwncat would like to be come a red team swiss army knife. Hopefully soon, more features will be added.
- More privilege escalation methods (sudo -u#-1 CVE, LXD containers, etc.)
- Persistence methods (bind shell, cronjobs, SSH access, PAM abuse, etc.)
- Aggression methods (spam randomness to terminals, flush firewall, etc.)
- Meme methods (terminal-parrot, cowsay, wall, etc.)
- Network methods (port forward, internet access through host, etc.)
Because pwncat
is trying to abstractly interact with any shell with minimal remote system
dependencies, there are some edge cases we have found. Where we find them, we do
everything we can to account for them and hide them from the user. However, some have
slipped through the cracks and been observed in the wild. When this happens, pwncat
will do whatever it can to preserve your terminal, but you may be greeted with some
peculiar output or command failures.
While BSD is a Unix-based kernel, in practice it's userland tools are noticeably
different from their Linux counterparts. Due to this, many of the automated
features of pwncat
will not work or outright fail when running against a BSD
based target. I have tried to catch all errors or edge cases, however there are
likely some hiccups which haven't been fully tested against BSD. In any case,
the stabilized shell should function within a BSD environment, but I don't
provide any guarantees.
If I find some time later down the road, I may try to stabilize pwncat
on BSD,
but for now my focus is on Linux-based distributions. If you'd like to
contribute to making pwncat
behave better on BSD, you are more then welcome to
reach out or just fork the repo. As always, pull requests are welcome!