Nscan is a fast Network scanner optimized for internet-wide scanning purposes and inspired by Masscan and Zmap. It has it's own tiny TCP/IP stack and uses Raw sockets to send TCP SYN probes. It doesn't need to set SYN Cookies so it doesn't wastes time checking if a received packet is a result of it's own scan, that makes Nscan faster than other similar scanners.

Nscan has a cool feature that allows you to extend your scan by chaining found ip:port to another scripts where they might check for vulnerabilities, exploit targets, look for Proxies/VPNs...

Nscan is a free tool, but consider donating here: 1Gi5Rpz5RBEUpGknSwyRgqzk7b5bQ7Abp2

Installing Nscan on Debian/Ubuntu boxes:

$ git clone https://github.com/OffensivePython/Nscan $ cd Nscan/latest $ chmod +x nscan.py 

Check if Nscan executes

$ ./nscan.py Usage: nscan.py x.x.x.x/x [options] nscan.py iface load/unload : Load/Unload Nscan alias interface nscan.py resume filename.conf: resume previous scan Options: -h, --help show this help message and exit -s STYPE Scan type S:SYN U:UDP (default=S) -p PORTS, --port=PORTS Port(s) number (e.g. -p21-25,80) -t THREADS, --threads=THREADS Threads used to send packets (default=1) --import=IMPORTS Nscan scripts to import (e.g. --import=ssh_key:22+check_proxy:80-85,8080) -b, --banner Fetch banners -n COUNT Number of results to get -o FILE, --output=FILE Output file -c N,T, --cooldown=N,T Every N (int) packets sent sleep P (float) (Default=1000,1) 

Nscan is simple to use, it works just the way you expect.

If this your first run, you need to load nscan alias interface before launching a Scan

$ ./nscan.py iface load Press enter key to load nscan alias interface [....] Running /etc/init.d/networking restart is deprecated because it may not [warnable some interfaces ... (warning). [ ok ] Reconfiguring network interfaces...done. Nscan alias interface loaded: 10.0.2.16 

To scan your local network for port 22,80:

$ ./nscan.py 192.168.0.0/16 -p22,80 _ __ / | / /_____________ _____ / |/ / ___/ ___/ __ `/ __ \ / /| (__ ) /__/ /_/ / / / / /_/ |_/____/\___/\__,_/_/ /_/ @OffensivePython 1.0 URL: https://github.com/OffensivePython/Nscan Scanning [192.168.0.0 -> 192.169.0.0] (65536 hosts/2 ports) [MAIN] Starting the scan (Fri Jan 30 07:11:02 2015) ... 

Scan the entire IPv4 address space for port 80

$ ./nscan.py 0.0.0.0/0 -p80 

use '-t' to specify how many sending thread you want to use, it decreases the elapsed time of the scan by n times:

$ ./nscan.py 192.168.0.0/16 -p3389,5900-5910 -t3 

This splits the 65536 hosts in 3 ranges (3 threads), every thread is going to scan 21845 host

use '-b' to grab banners and '-o' to save logs in a file

$ ./nscan.py 192.168.0.0/16 -p3389,5900-5910 -t3 -b -o nscan.log 

In order to stop the scan after receiving 10 results:

$ ./nscan.py 192.168.0.0/16 -p443 -b -n10 

To import Nscripts, use '--import' with filename (without extension '.py') and specify the port and/or range of ports

$ ./nscan.py xxx.xxx.161.152/24 -p1080 --import=proxy:1080 _ __ / | / /_____________ _____ / |/ / ___/ ___/ __ `/ __ \ / /| (__ ) /__/ /_/ / / / / /_/ |_/____/\___/\__,_/_/ /_/ @OffensivePython 1.0 URL: https://github.com/OffensivePython/Nscan Scanning [xxx.xxx.161.152 -> xxx.xxx.162.0] (104 hosts/1 ports) [MAIN] Starting the scan (Fri Jan 30 09:14:14 2015) [SEND] Sent: 104 packets [RECV] Received: 7 packets [MAIN] xxx.xxx.161.152:1080 [MAIN] xxx.xxx.161.173:1080 [MAIN] xxx.xxx.161.195:1080 [MAIN] xxx.xxx.161.196:1080 [MAIN] xxx.xxx.161.194:1080 [MAIN] xxx.xxx.161.239:1080 [MAIN] xxx.xxx.161.193:1080 [PROXY] xxx.xxx.161.152:1080 | SOCKS4 [PROXY] xxx.xxx.161.195:1080 | SOCKS4 [PROXY] xxx.xxx.161.196:1080 | SOCKS4 [PROXY] xxx.xxx.161.194:1080 | SOCKS4 [PROXY] xxx.xxx.161.193:1080 | SOCKS4 [MAIN] Packets sent in 0.0 minutes [MAIN] Total elapsed time: 0.7 minutes [MAIN] Done (Fri Jan 30 09:14:58 2015) 

Every ip has the port 1080 open, will be chained to the Nscript proxy, which checks if a SOCKS service is running behind it.

This will chain every ip:port that has the port 1080,3127,3128,3129 open:

$ ./nscan.py xxx.xxx.xxx.xxx/xx -p8080,1080,3127-3129 --import=proxy:1080,3127-3129 

P.S: Port 8080 will not be chained to the script, since it's not specified

If you have a large range of hosts to scan, and your bandwidth can't finish the scan really quick, You can suspend a scan and resume it later where it's stopped.

To suspend a running scan, hit [CTRL]+C, Nscan will save where it's paused in 'resume.conf'. The resume configuration file looks something like this:

$ cat resume.conf [NSCAN] hosts = [167772160, 184549376L] ports = [[80, 81]] threads = 1 imports = None banner = True count = None output = None indexes = [(16777216L, 4194304L, -249, 16776967L, 249)] cooldown = (1000, 1.0) 

To resume a previous scan, simply type:

$ ./nscan.py resume resume.conf 

This is a very important option to regulate Nscan with your bandwidth, If you don't choose this properly, Nscan will probably knock off your router and force it to restart since it sends more traffic than your router could handle. You can specify the number of packets that needs to be sent before Nscan should cool down and sleep for a while

$ ./nscan.py 10.0.0.0./16 -p21-25,8080 --cooldown=100,0.1 

This tells Nscan, "for every 100 packets sent, sleep for 0.1 second(s)" P.S: The size of one packet is 54 bytes

If you have a gigabit Ethernet connection, you probably want to disable this:

$ ./nscan.py 0.0.0.0./0 -p21-25,8080 --cooldown=[ANY],0 

Every nscan script should have a run() function, that takes two arguments:

queue: queue where your script receives ip:port

event: This tells your script that Nscan is completed the scan, and waiting for your script to finsish before it exits

Make sure that your script is under '~/nscan/nscripts' folder.

Every Nscript has this simple skeleton:

importQueueimportlogging# Import any module you need heredefrun(queue, event): whileTrue: ifqueue.empty() andevent.isSet(): # If the Scan is completed and the queue is empty (no more results)breakelse: try: ip, port=queue.get(False, TIMEOUT) # Should be non-blocking# Do something useful with IP:PORTexceptKeyboardInterrupt: # Scan suspended, should exitbreakexceptQueue.Empty: # No resultspass

Use the logging module to output your results:

SCRIPT = 'MYSCRIPT' logging.info('[{}]{}:{} |{}'.format(SCRIPT, IP, PORT, 'MY RESULTS')) 

Tips, Requests, Improvements to make Nscan more stable and faster are always welcome.

If you want to share your Nscripts with everybody, tweet me at @OffensivePython #Nscan with a link of your script, and i will add it under the nscript folder here

• UDP Scan Support
• PPP interfaces Support