Tag Archives: BIOS

Posts

Weaponizing the Nokia N900 – Part 3.5

8 Comments

Due to my love of hand held devices that can be used for penetration testing, I have obtained a Nokia N900 for relatively cheap on eBay. A brand new N900 will burn you a hole about the size of $399 USD in your pocket. However, I obtained mine (a refurbished one) for about $285.

Granted this device is now 2 years old but in my opinion it can be setup as a solid security assessment tool. I thought I would write a de facto continuation of the “Weaponizing the Nokia N900″ series that Infosec island has done. (I hope they don’t mind 🙂 )

With the N900 being an old man, in terms of technology, one can spruce it up a bit via overclocking. I would highly suggest to check out:

http://thehandheldblog.com/2010/07/27/how-to-easily-overclock-your-n900-in-under-two-minutes/

I have mine overclocked to 750MHZ and it seems to be running just fine. Metasploit will load in about a minute or so. Which is not nearly as bad as running Metasploit on the N810 (which I was able to do by just following the same instructions for getting Metasploit to run on the N900). The N810, the last time I checked, took 15 minutes to load Metasploit.

Bear in mind that my tips imply that you have already enabled all the extra repositories as needed, if you haven’t done so check out:

http://www.nokian900applications.com/repositories-extras-extras-devel-and-extras-testing-for-nokia-n900/

As stated and shown before, there have been guides on weaponizing the N900. However some of these guides have failed to explain certain issues that I would like to address:

1.) The ettercap-ng package from the repositories is totally broken. I ended up having to download ettercap from this forum post and follow the instructions on it appropriately:

http://talk.maemo.org/showthread.php?t=42680

2.) sslstrip will work, and you have to follow the comments addressed on this web page to get it setup along with a few other things:

http://www.knownokia.ca/2010/04/using-n900-for-fun-and-profit.html

a.) You have to install iptables  (apt-get install iptables)

b.) You have to install another python package, (apt-get install python-openssl)

3.) The Metasploit package comes in in a tar.bz2 format. For some odd reason, the version of tar (the busy-box version) cannot do ‘-xjf’. So either you have to install the gnu version of tar or put metasploit on a computer that can extract it and put it into a format that can be decompressed on the n900.

4.) I wasn’t able to find netcat in the repositories. If you’re in the same boat, you’ll have to port it over or get a chroot environment setup. (easydebian)

Lastly, here is my original way of weaponizing the n900 even more so.

You’ll need a MicroSD card that you’re currently not using and you don’t mind wiping it and making it bootable. Also, you’re going to need BackBox iso (yes.. not BackTrack 4, I will explain later) and unetbootin.

Obtain BackBox from:

http://www.backbox.org/content/download

Obtain unetbootin from:

http://unetbootin.sourceforge.net/

1.) Install your Microsd card into the N900, by removing the back plate.

2.) Connect your n900 via the USB cable that came with it to your N900.

3.) When you get a prompt on your n900 from connecting it to your computer, choose the Mass storage device mode.

4.) Now, 2 drives should show up, (depending on if you’re using Windows or if you have automount setup under Linux). The drive that is the size of your MicroSD card, is your MicroSD card. (I know.. DUH)

5.) Fire up unetbootin, select Diskimage option, locate where you downloaded the BackBox iso and select it.

6.) Make sure you have the correct drive selected and finally click ‘OK’.

7.) Once the process is done, reboot your computer.

8.) Hit F2 (or it could be other keys, like F9) for your BIOS or better yet if there is an option for a boot menu, hit that key.

9.) Select to boot off of the N900 (some BIOS will show two and not differentiate the two, while other BIOS will state that there is a removable n900. If you’re not sure, just change your boot order to have both N900’s as the first and second boot devices. If your BIOS shows the removable N900, this is the one you want to boot off of.)

10.) Your computer should now be booting off your MicroSD card which is in your N900.

The real cool thing here, is that you can still use your N900 while the computer has booted off of your N900. So you can still make phone calls or surf the net with it.

Now you may be asking yourself, “Why would I want to do this?”. I ran through a couple scenarios in my head, the first, is if you only have one USB drive that is currently in use running, say L0phtcrack on one workstation, but you want to multitask and still explore the network further. Well you have your handy and now bootable N900. Lastly, it seems as if most computers (from my experience) don’t have a MicroSD card slot but have USB ports.

Finally, I naturally tried BackTrack 4, but it would not boot and it would shove me to a busybox shell. I didn’t feel like dealing with finding a fix at the time, so I thought I would find a different distro.

If I do more interesting and original things with my N900, I will post more.

As usual more to come…

Posts

Boot Sequence Attacks

Leave a comment

There’s a saying amongst a few fellow computer security enthusiasts that I know of, that goes a little something like this, “If the attacker has physical access to the machine, the game is over.” (Or something to that extent)

This couldn’t be any further from the truth. If I were to do a permitted pentest upon a company which included physical access as part of the scope, then I would definitely test the local workstations and use one of them as a pivot point to gain further access/information.

To mitigate this attack, the administrator should ideally change the boot sequence to have the hard drive as the first device the computer boots from in the BIOS and also set the BIOS password, and have the computer case locked down, so one couldn’t clear the CMOS (it’s usually jumper 1 on the motherboard).

However, in most large facilities, administrators usually don’t take the time to do this and are usually more concerned with other types of attacks, in my opinion.

Now I will give a hypothetical scenario for a pentester that will permit him/her to do a pentest that will include physical access to this factitious facility.

Upon gaining physical access to a workstation, the pentester has a few tools with him/her. In his/her arsenal he/she has as follows:

BackTrack 4 on a USB flash drive
PLoP ( http://www.plop.at/en/bootmanager.html )
Konboot ( http://www.piotrbania.com/all/kon-boot/ )
cmospwd ( http://www.cgsecurity.org/wiki/CmosPwd )

As the pentester reboots the computer and tries to enter the BIOS, he/she is stopped by a password prompt. In the password prompt, he/she tries a few combinations including backdoor passwords that are sometimes set by manufacturers. ( http://www.uktsupport.co.uk/reference/biosp.htm )

Realizing that none of these worked, the pentester needs to then assess whether or not the administrator has locked down the boot sequence.

Out comes the flash drive and into the USB port it goes! The pentester is aware of how some motherboards will default to the USB drive as the first boot device when plugged in. (I’ve personally experienced this on a motherboard I own). However, still no luck!

With the pentester’s lock picking skills not at their best, he/she is detoured by the workstation’s case lock. It is time to him/her to revert to PLop.

PLop is one beautiful tool. It is a boot manager that you can even use on old motherboards that don’t support booting off of flash drives.

The pentester was in luck! The workstation checked the CD-ROM drive first in its boot sequence! Now the pentester can direct the victim workstation to boot off his USB drive (with Backtrack 4) via PLop.

Upon getting the prompt from Backtrack 4, the pentester is now curious about what the password was set to on the workstation.

To find this info, he/she uses cmospwd. By retrieving this password, the pentester can use this as leverage towards other devices in the network.

I’ve had luck with some motherboards using cmospwd for retrieving the password from the dump it can produce. Consequently, it’s not perfect, but it can get the job done.

I know I mentioned konboot as part of the arsenal but didn’t have the pentester use it, but I thought I’d mention it due to the fact it’s such a wonderful tool to have.

I’ll have more to come as usual and I have two programs in mind that I’m working on..