Nmunch is a simple passive network discovery tool to find live nodes just by listening to ARP and broadcast packets on a network interface.
The main reason why I built this tool was mostly to have an excuse to play around with the ruby-pcap gem, but it turned out to be quite useful and the architecture is flexible enough to extend the tool to do pretty much anything with a discovered node.
- Ruby 1.9
- libpcap (http://www.tcpdump.org/)
gem install nmunch
Nmunch is pretty straight-forward and supports two different methods:
Listen on a network device
nmunch -i <device name>
To find the names of your network devices, use
ifconfig in a terminal. Usually,
they are called
To stop listening, simply press
C to interrupt. It might take a couple of
seconds before it reacts.
Analyze a PCAP capture file
Nmunch can also find nodes from a
pcap capture file:
nmunch -f <path/to/pcap/file.pcap>
See all options
To see all options for Nmunch, type:
I have tried to keep the architecture pretty flexible with a simple publish/subscribe pattern for handling the discovered nodes. So if you want all nodes to be pwned by your secret 0day spl0itz, you can write a new node subscriber to do that for you. Have a look at
Nmunch::Subscriber::Stdout for an example of how to write a node subscriber
Y U NO capture [insert protocol name] to find more nodes!?!1
The current version of Nmunch only looks for ARP and broadcast IP packets which captures quite a lot of nodes, but if you have more ideas, you can easily make a new packet dissector to handle it. see
Nmunch::Dissectors::Arp for an example of how to write a packet dissector.
This is what I have on the roadmap for Nmunch:
▢ More tests
▢ Improve documentation
▢ Export results in formats compatible with other tools
▢ Easier way to register custom node subscribers
▢ Extract more interesting information apart from live nodes
▢ Make a Metasploit Auxiliary module version of Nmunch
Feel free to file an issue, even if you don't have time to submit a patch.
Please try to include tests for any patch you submit. If you don't include tests, I'll have to write one, and it'll take longer to get your code in.
Copyright (c) 2012 Michael Henriksen
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