Blackhole

Blackhole is a low-interactive Honeypot that captures and logs everything. Using iptables all incoming TCP and UDP request are redirected to a single port, hence it seems as if the Honeypot is listening on all ports. Telnet(23) and HTTPS ([0-65]443) requests are supported in a limited way. The Honeypot was written as a PoC to capture all requests and so, has limited features.

Blackhole is not an ideal Honeypot, but is very useful for capturing IPs and Raw requests of automated scanners.

Minimum requirements:

Debian with Python 2.7.9 and gevent package.

Setup:

git clone https://github.com/dudeintheshell/blackhole.git
cd blackhole
sudo apt-get install python-virtualenv python-setuptools python-dev build-essential
virtualenv env
source env/bin/activate
pip install gevent

Create SSL certificate :

(http://blog.justin.kelly.org.au/how-to-create-a-self-sign-ssl-cert-with-no-pa/)

This is required to support HTTPS request.

Generate key with openssl

openssl genrsa -out ssl.key 1024

Create ‘Certificate Signing Request’ - and leave the passwords blank

openssl req -new -key ssl.key -out ssl.csr

Create SSL certificate

openssl x509 -req -days 366 -in ssl.csr -signkey ssl.key -out ssl.crt

Setup iptables rule

If you want to redirect all TCP and UDP traffic to Blackhole use the following command:

sudo iptables -t nat -A PREROUTING -p tcp --dport 1:65535 -j REDIRECT --to-ports 5000
sudo iptables -t nat -A PREROUTING -p udp --dport 1:65535 -j REDIRECT --to-ports 5000

Suppose you have other services running on the Host e.g. 22, 445 and you don't want to capture them via Blackhole,you can create multiple iptables rules:

sudo iptables -t nat -A PREROUTING -p tcp --dport 1:21 -j REDIRECT --to-ports 5000
sudo iptables -t nat -A PREROUTING -p tcp --dport 23:444 -j REDIRECT --to-ports 5000
sudo iptables -t nat -A PREROUTING -p tcp --dport 446:65535 -j REDIRECT --to-ports 5000

Making nf_conntrack readable:

Since Blackhole listens on port 5000, its is hard to tell which port got the original request. Using nf_conntrack/ip_conntrack we can identify the actual port to which the connection was requested. If the Blackhole runs with lower privileges, we need to make nf_conntrack readable for others:

chmod +r /proc/net/nf_conntrack

OR

chmod +r /proc/net/ip_conntrack

Running Blackhole

Once everything is ready, go to the Blackhole's directory and execute the following commands:

source env/bin/activate
python blackhole.py

All captured data and binaries are stored in "captures" directory. Logs are stored in the "logs.txt" file.