Getting to know your neighbors — Darren takes a trip around your network with nmap, THE open source network security scanner. Want to obscure your OS fingerprint? Make a Windows Box show up as a printer? Shannon’s got just the thing. And Matt takes a first look at the Napera N24 smart network switch / security appliance. All that and more on this Hak5 Season 5 Premiere!
Taking a trip around your network with Nmap
This week I talk about network scanning with the difinitive open source security scanner Nmap.
Scanning ones own network is ideal whether simply to know your neighbors or keep inventory of your assets. As a black hat it can be the first step in enumerating a target environment and looking for weaknesses.
In order to perform our scan we’ll simply need a copy of Nmap. It’s available for Windows, Mac, and just about every flavor of Linux, BSD and more. If you’re on a debian based system like Ubuntu a simple apt-get install nmap should do you good. If you’re looking for a security distribution with nmap (and a ton of other great tools) built in can’t speak highly enough of BackTrack. Version 4 beta was just recently released.
The underlying workings of Nmap are better explained in this guide but suffice it to say it takes advantage of TCP’s 3-way-handshake and other fancy raw packet tricks to find hosts and open ports. In this segment I set out to introduce the concept and get you started with a few basic examples. If you’re interested I recommend Nmap Network Scanning and the official man pages as further reading.
The segment details some commands and their usage in a searching for open MS terminal servers scenario. I highly encourage you to provide feedback either by way of email (darren AT hak5 d0t org) or on our forums. I enjoy doing segments like these but if you have any corrections (more than one way to skin a cat), suggestions for future topics or hacks of your own please let me know.
Obscure your OS Fingerprint
OSfuscate 0.3 by Irongeek is used to camaflouge or obscure your Windows OS. With this tool, it’ll show up like another OS of your choice, nothing at all, or even a printer. OSFuscate could be used if you are on a hostile network and need some sort of cloak while going along in your daily routine. It is important to note that this is not a fool proof method for hiding yourself on a network and should not be relied upon for security. however, as a layer of obscurity in addition to your regular security practices you may want to consider it.
It’s a simple process to set up OSFuscate on your machine. Go to Start->Run->Regedit. Back up your Parameters folder, found under System->CurrentControlSet->Services->Tcpip->Parameters. You can do this by simply right clicking on the folder, and choosing export. This is basically just to keep yourself form messing up your OS in the process and having no way to return it to normal. You’ll notice on Irongeek’s website that certain Parameter Registry keys will be subtly changed. You could do this by hand, but OSFuscate makes this task super simple. Open OSFuscate, and choose an OS that you want to pretend to be. Restart your computer and the differences should be in place! Now if someone running NMap snoops your computer, they’ll see some other OS other than what you actually have.
as it really helps us out.
Matt’s full review of the Napera N24 can be found on his blog at MattLestock.com.
Thanks for tuning into our season premiere episode. We’re very excited about all of the exciting new projects coming up in Season 5. We appreciate and encourage your feedback — especially on this episode’s fresh format, pace, and presentation. We strive to make this show better and better for you every week so let us know how we’re doing!
And a big thanks to those who’ve contributed to the success of Hak5. Your donations are greatly appreciated!