Aten Labs

So when I get a new phone, I immediately want to try to get as much access on it as possible (read: root it). Custom roms are wonderful, but in the case of the HTC Incredible I don’t think there are custom roms (yet).

After I rooted my HTC Incredible I started doing searches in the market for interesting things. I found some neat wireless utilities, I found a file manager that lets you browse SMB fileshares on the lan (NEAT.), I found a packetsniffer, and some more interesting tools.

The light came on over my head when I realized “Wait, a packet sniffer AND a wireless access point? .. can .. I sniff.. the wifi with this?!”. As it turns out the answer is yes – it takes some fenagling, and if you do it in the wrong order one application stomps the other (I’ve already written the author of the packet capture application about this but have not gotten a response yet).

Here is a quick walkthrough on how to turn an HTC Incredible into a rogue wireless access point:

1. Root the phone. This can be done by visiting http://unrevoked.com/recovery/, downloading the app, and running it.
2. Once the phone is rooted, go to the market, and install the wifi tether application: Be aware though, that with the HTC incredible there are additional steps to get this application to work (see their wiki page: http://code.google.com/p/android-wifi-tether/)

   

3. Install the packet capture application. This also will need additional steps after the installation. (http://sites.google.com/site/androidarts/packet-sniffer)
4. Once you have the packet sniffer installed, configure it to log to a file instead of a sql database. I wasn’t able to find the actual database this thing logs to, but the text file appears right at the root of the sdcard. It looks just like the ‘live’ output though, which I don’t think is a proper format. It doesn’t log raw traffic at all.
5. Don’t start the sniffer or wifi tether yet – they must be configured beforehand.
6. Go back to wifi-tether and configure the SSID. Name it something which will attract people in search of free wifi. Linksys. Dlink. Netgear. 2WIRE858. The SSID of a target network, perhaps. Again, do not turn on tethering here yet.
7. Open up the packet sniffer again, and go to the ‘wifi capture’ section, then enable the capture, and if you’d like, enable logging packets to the screen.
8. Hit the phones ‘home’ button to exit without stopping the packet capture tool, and re-open the wifi tethering tool. Once in the tethering tool, enable tethering.
9. Hit home again, and go re open the packet capture tool. If anybody connects, wifi tether will tell you in the status bar at the top of the display, and you will start seeing arp traffic and dhcp traffic scroll in the live feed window as you would with any other packet sniffer.
   

There are several caveats to this though:

1. This tool appears to not capture raw packets. You can do this from a terminal using TCPdump if you feel so inclined – the packet capture tool installation instructions have you install a new version of tcpdump. You should be able to use this to capture raw traffic and not just clear text
2. Packet capture has to be running before wifi tether – if you try to do it the other way around wifi tether will hang and you’ll have to kill it.
3. This will also capture all the traffic from your phone to the internet, so if you’re trying to do a bunch of stuff on your phone while running a rogue access point, it will  muddy your results.

This has been a fairly simple howto – you creative types will easily be able to find more interesting things to do with this.

My wishlist after figuring this out? – An app that acts like airodump – I want to see clients probing for networks so that I can “give them what they want”. I also want this packet capture tool to log raw data, not just plaintext stuff.  Now that this is possible, I wish for tools like drifnet, dsniff, and others of that sort to become available on the android platform. The objective here would be to use this during a pen test as a tool to capture data, then bring it back to the labs for analysis.