A few days ago there was some complaint from Climate Camp that there was a lack of mobile phone connectivity. There’s three reasons this can happen, in descending order of likeliness – the current cell is running at capacity, part of the network has gone down, a new fake base station has been introduced. The most interesting reason is the latter, so let’s explore that a little.

According to the GSM specifications, communications between the mobile and the current base unit are generally (but don’t have to be) encrypted, mobiles are authenticated before being allowed to connect to the network, and mobiles connect to the base station with the most powerful signal. This means that in countries where encryption is illegal, GSM can still be used. It also means that anybody can introduce a fake GSM base station in order to monitor communications, you just bring along a base station from the Iraqi network and make sure that the mobile units can’t communicate with the real base stations.

Needless to say getting your hands on an Iraqi cellular base station is easier said than done, especially where you also need the mobiles to be able to communicate with the outside world, but it’s still possible. It certainly seems to make more sense than trying to get all of the uk mobile networks to give you call records, mms/sms records and recordings of everything.

The much more likely reason there’s been problems making calls is simply that there’s a much larger number of people than usual in a somewhat rural part of the country. It may or may not be assisted by the cops restricting communications to make planning actions difficult, but most likely not.

Robots.txt

Our initial analysis of robots.txt files from a list of 94,593 hostnames gave some interesting results, although we need a lot more work to build the anti-search engine (one which only lists things denied by robots.txt files). The first crawl started generating errors after 812 hosts were connected to though, which gives us limited amount of data to analyse (and means we need to rethink the rough and ready scripts).

Of the 812 hosts, we have 732 robots.txt files with a total of 8935 disallow entries. Taking into account duplicate entries (where a file has an entry for the same path twice) there are 7517 unique disallowed urls to consider. Lets have a search for interesting entries.

There are:

• 29 entries including ‘private’, 8 of which are for Frontpage _private
• 8 entries including ‘secret’
• 27 entries for ‘password’, although most seem innocuous
• 148 entries for ‘admin’, although we assume most will be passworded
• 12 entries for ‘secure’
• 11 entries for ‘backup’
• 69 entries for ‘mail’, including webmail, spam bait, mailing list signups and mail logs
• 493 entries for ‘log’, although many of these are blogs and not interesting logs or login pages
• 6 entries for ‘phpmyadmin’
• 30 entries for ‘stats’, not all of which are webstats (‘stat’ gives 157, but again many are false positives)
• 62 have comments as to why they are disallowed

Don't hack the hackers

Sometimes you need to be extremely careful what you are hacking into, take the following hypothetical situation:

Walking through town, I was keeping one eye on my frequency counter as I quite often do.  Passing through the main shopping street I spotted a transmission in the 1.5Ghz band, it’s hard to be exact with my cheap frequency counter.  Interested, I wandered around trying to find the source and discovered it was strongest on one side of the street between a phone shop and a bank.  So I stood around for a while, waiting to see if I could eek out the source or see any likely candidate.

It’s then that I spotted the bank’s cash machine, and vaguely wandering towards it the signal got stronger.  Cash machines aren’t supposed to transmit anything, and it took me longer than it should have to realise that somebody had attached a card reader and wireless camera in order to steal peoples credit card numbers.

I then smoothly put my counter away and started walking, just before two mounted policemen turned round the corner and started to approach the bank…