91 lines
4.3 KiB
Markdown
91 lines
4.3 KiB
Markdown
<!--
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Copyright (C) 2023 Andrew Rioux
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Affero General Public License as
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published by the Free Software Foundation, either version 3 of the
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License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Affero General Public License for more details.
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You should have received a copy of the GNU Affero General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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-->
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# Sparse 0.5
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Sparse 0.5 is a stopgap solution until the C2 framework itself is more mature. It has several improvements over the proof of concept version, to include:
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- The client is no longer bound to the server, the configuration can be shared
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- A richer CLI with Sparse specific commands such as #upload, #download, and #edit
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- A Windows version using winpcap, with both standalone binary and service versions
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# Obtaining
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Sparse 0.5 is immediately ready to build from source if using the [Nix package manager](https://nixos.org/download) [with flakes enabled](https://nixos.wiki/wiki/Flakes) by running `nix build .#sparse-05-client`.
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## FreeBSD support
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Building normally will only produce a client that can generate beacons for Linux and Windows, lacking proper FreeBSD support. To build the client with FreeBSD support, create a FreeBSD build environment by running `vagrant up` and compiling a FreeBSD sparse binary by running `sparse-build` or `sparse-build --release`. With the FreeBSD binary built, copy it from `target/x86_64-unknown-freebsd` to `sparse-05/sparse-05-freebsd-server`, and rebuild using Nix
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Currently, there are no prebuilt binaries. However, sparse can easily be built if the [Nix package manager](https://nixos.org/download) is installed. Just clone this repository and run `nix build .#sparse-05-client` and the client will be placed in `result/bin`.
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# Use
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Using sparse centers around the client. The client can generate new servers as well as the configuration file necessary to connect to the server, connect to a server for a shell, and verify the connection against a server.
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## Generating a new server
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Sparse supports 4 different targets:
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- Linux
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- Windows
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- Windows service
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- FreeBSD
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The basics center around `sparse-05-client generate <name> [-p <port>] [-t <target>]`. This generates both a server and the configuration file necessary to connect to the server.
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If the port is not specified, it defaults to 54248.
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### Linux
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To install the Linux service, there are a few options:
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- Run as root
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- Run with CAP_NET_RAW and CAP_SETUID as a non-root user
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- Run in a Docker container running as root on Linux with kernel version 5.13 or greater and the `--privileged` and `--pid=host` flags
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### Windows
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The Windows version requires an installation of winpcap 4.1, which can be downloaded from [their website](https://www.winpcap.org/install/default.htm).
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As of Jan 25 2023, Windows Defender is suspicious of exe builds of the sparse server but only tries to submit samples and does not declare it malicious.
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### Windows service
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The Windows service has the same requirements, but can be installed with `sc create <service name> DisplayName= <service name> binPath= <service exe path>`.
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As of Jan 25 2023, Windows Defender marks the Windows service binary as malicious
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### FreeBSD
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Create a service to run the resulting binary as root
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## Connect
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After installing and running the server, it is possible to connect using the generated `scon` file and `sparse-05-client` with `sparse-05-client connect <name>.scon <service ip>:<service port>`.
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This brings up a shell that can run commands. However, there are special commands that are injected:
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- `#help`: shows sparse specific help
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- `#sysinfo`: prints information about the system being connected to
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- `#upload [local] [remote]`: uploads a file from the local path to the remote path
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- `#download [remote] [local]`: downloads a file from the remote path to the local path
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- `#edit [remote]`: downloads a file remotely and opens it in `$EDITOR`, and uploads the final version
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## Connection test
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To verify that an installed service is still alive and working, run `sparse-05-client connect-test <name>.scon <service ip>:<service port>`
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