First and foremost I am not taking credit for the act of this. There are other posts on getting Bactrack 5 (ARM) onto the N900. My post mostly pertains to my experience with Backtrack 5 on the N900 and how viable of a offensive information security tool it is.

If you’re curious as to how to get Backtrack 5 running on your N900, you want to thank SuperDumb from the Maemo forums, and take a look at this forum thread. Observe that the default Backtrack 5 (arm) image will not copy over to your vfat microSD external or internal cards. vfat has a file size limit

There are some guides that advocate using ext2/3 on flash devices, but I do not condone you doing this, please see:

http://www.linux.com/archive/feature/114295

To circumvent this issue you can download an image that will work on vfat here, or if you would prefer to re-size the image yourself, follow these steps that SuperDumb graciously gave me via a PM:

Must be done under linux :
Just an example, change the dirs how you want them :

First you need to get the bt5.img out of the downloaded file from backtrack :

These are the steps to get a img that is small enough :

After that just umount bt5old & bt5new and you should have a working img.

Once you have a working img, you will need to have qchroot on your N900 along with gainroot. Then to get Backtrack 5 running on your N900 via the non-GUI way, you simply do as follows:

1.) sudo gainroot

2.) mkdir /mnt/bt5

3.)qchroot /location/to/bt5.img /mnt/bt5

One important note I would like to add with regards to the location of the bt5.img file, is that if you’re like me and you have a bootable linux distro on mmc1, you will not want to have the bt5.img on mmc1. Once your computer mounts the mmc1 card, your mmc1 card will not be accessible via your phone.

You can get VNC up and running, however the N900 keyboard and the Backtrack 5 GUI (at least using gnome) do not get along that well. Additionally, it is resource intensive and if you ask me, to truly utilize Backtrack or almost any Linux distribution, you want to use the command line interface. This is where the power lies. There are a few exceptions to this rule but exceptions don’t necessarily make the rule.

In my humble opinion having Backtrack 5 running on your N900 is not really worth it. My reasoning is due to my experience with it. Here are a couple instances of annoyances that I ran into:

– It is unstable. There were a few times that I would make an attempt to edit sources.list, via:  ‘vi /etc/apt/sources.list’ and my phone would randomly reboot.

– The GUI does not work well at all.

– There are packages that are easily available under the N900, that aren’t easily available under Backtrack 5 (ARM). (kismet for example.)

– Some packages are just broken. For example, miredo does not work at all. (More on miredo later…)

– Nmap’s version under BT5 arm is 5.00 and you can get Nmap for maemo on the N900 at version 5.50.

– easydebian seems like a better alternative and is more stable.

I’m going to go on a bit of a tangent here that I hope is informal and useful.

With miredo not working under BT5 on the N900, that was kind of a big annoyance to myself because miredo for the Maemo even appears to be broken as well.  To get miredo working on your N900 you will want to install and use easydebian.

What is beautiful with miredo, is that you can get an IPv6 address assigned to your N900. You could then use your N900 as a hardware based trojan in a network. The whole concept is very similar to what Mubix did here. You could setup your N900 on a victim network and have ssh listing on your public IPv6 address and then log in to your N900 from an outside network over IPv6. You wouldn’t even have to do any port forwarding on the victim’s firewall/gateway/router.

I will tell you that miredo does not work on all networks and does not appear to work over the gprs0 interface on the N900 (at least with my carrier). Though it works just fine on the wlan0 interface.

Readjusting back from that tangent, summarily I would like to state that the fact that you can get Backtrack 5 working on your N900 is wonderful. Consequently, due to my experience with running BT5 on the N900, I would just advise to use easydebian over BT5 and then customize easydebian to the point that it is essentially a ‘Backtrack’ version. It will be a more stable route to go and you can learn about the tools as you install them, versus having a plethora of tools at your disposal that you may not get around to learning.