pyUpDown

Basic HTTP(s) Web Server with upload and download.

This server is designed to:

1. Run with no dependencies apart from standard Python libraries.
2. Return every file as text/plain.
3. If requested, return files base64-encoded (think powershell -encodedCommand...) or XOR'd with a key of your choice
4. Allow for file upload

Its purpose is to aid in exfiltrating data during a penetration test (use socat to run it over ssl - see below) and transfer scripts, commandlets and binary data.

WARNING The server will bind on 0.0.0.0:8080 by default. Don't leave it listening over the open internet unprotected.

Quickstart

chmod +x s.py
./s.py

Then:

$ echo "hello" > test.txt
$ curl 'http://localhost:8080/test.txt'
hello

# just base64-encode the result
$ curl 'http://localhost:8080/test.txt?b64=1' 2> /dev/null | base64 -d 
hello

# XOR the file with the key '123' and base64-encode the result
$ curl 'http://localhost:8080/test.txt?key=123'
WVdfXV05

# upload stuff from a web browser:
# visit http://localhost:8080/upload

# upload stuff from the command line
$ curl 'http://localhost:8080/upload' -F upload=@file.txt

For more options:

./s.py -h

SSL Support

To run the whole thing over SSL, use socat:

1. Generate a certificate and a private key into the same file. Do this once:

   openssl req -x509 -newkey rsa:2048 -nodes -subj "/CN=localhost" -keyout cert.pem -out cert.pem -days 365
   

2. Run the server and keep it running:

   ./s.py
   

3. From a different shell, use socat to connect to the server:

   socat openssl-listen:8443,verify=0,cert=cert.pem,reuseaddr,fork tcp4:localhost:8080
   

4. Connect to https://localhost:8443

For socat with letsencrypt:

socat openssl-listen:443,fork,verify=0,cert=/etc/letsencrypt/live/yourhost/cert.pem,key=/etc/letsencrypt/live/yourhost/privkey.pem,reuseaddr tcp4:localhost:8080

Miscellanea

Use the -d command-line flag for verbose debugging messages.