nmap/ndiff based scanner with template based notification system in case of infrastructure changes

In situations you want to keep track of your network configuration (in this context: variation of open ports over time), nmap and ndiff come in handy.

This script tries to solve a problem if you have to track several networks or individual hosts that you want to scan consecutively. In case a network change is detected, the difference is sent in a (templated) mail to a configurable recipient.

git pull this repository at a location of your choice. Make sure nmap and ndiff are installed. Sending emails should be working from command line using the mail command. logger is being used for logging. The user running the script should be in the sudoers file, especially for running nmap:

username ALL=NOPASSWD: /usr/bin/nmap

There are a few options in the example config file that can be changed, as well as all the templating for the mails. Copy the config file scan.conf-example to scan.conf and edit it accordingy your wishes.

./scan.sh [IP]/[CIDR] [Email address]

Create a file called targets (see targets-example to get an idea) and define your targets, notification addresses and nmap options there. When reading from a file, -r needs to be specified to deal with the special condition.

cat targets |parallel -j 4 ./scan.sh -r {}

You can tune the number of parallel tasks with the '-j n' parameter.

This email contains information regarding a subsequent network port scan performed 
by ORG, which discovered a network change.
Hereafter the result of the scan and the changes (additional open ports or new hosts 
indicated by a plus ('+') sign, closed ports indicated by a minus ('-') sign) 
regarding the network 127.0.0.1/32:
PORT    STATE         SERVICE VERSION
22/tcp  open          ssh
25/tcp  open          smtp
+23/tcp  open          Telnet

If this network change was unexpected, please review what caused the change and 
react accordingly. 

Copyright: Sascha Rommelfangen, CIRCL, Smile g.i.e, 2018-01-31

GNU General Public License v2.0

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