Modern Freaking: Pull Phone Numbers From YouTube Audio

February 13, 2011 by Mike Szczys 48 Comments

[Charlie X-Ray] is having some modern fun with the phone system by pulling dialed numbers from the audio track of YouTube videos (translated). The first step was to find a video where a telephone is being dialed and the sounds of the keypresses are audible. You can’t tell those tones apart, but a computer can. That’s because each number pressed generates a combination of two out of seven closely related frequencies. [Charlie] isolated the audio using Audacity, then wrote a python script to generate a spectrogram like the one above. By matching up the two dark nodes you can establish which two frequencies were played and decode the phone number being dialed. So how does this work again… find audio of a phone being dialed, decode the number.. profit?

SMS Controlled Irrigation

February 12, 2011 by Mike Szczys 10 Comments

[Mhkabir] built an irrigation system that communicates by text message. The concept is simple, sending a text message to the system will cause it to switch on the water pump.

Many times we see text message manipulation via the Internet, or using a GSM module. But in this case an inexpensive cellphone is used as the communication interface. The vibration motor has been removed and those connections are monitored to signal incoming messages. Wire leads were soldered to the keypad contacts which allow an Arduino to send out text messages when there is a problem with watering. This isn’t an iron-clad system, as any incoming message will trigger the system and outgoing messages are limited to saved drafts. But a bit of creative programming and we’re sure more functionality could be squeezed out of this hardware.

Going Cellular With Your Arduino Projects

February 5, 2011 by Mike Szczys 44 Comments

You can add a huge measure of extensibiltiy to a project by using a cellular connection. Anywhere the device can get service you can interact with it. In the past this has been a pretty deep slog through datasheets to get everything working, but this tutorial will show the basics of interacting with phone calls and text messages. It’s the 26th installment of what is becoming and mammoth Arduino series, and the first one in a set that works with the SM5100B cellular shield.

We love the words of warning at the top of the article which mention that a bit of bad code in your sketch could end up sending out a barrage of text messages, potentially costing you a bundle. But there’s plenty of details and if you follow along each step of the way we think you’ll come out fairly confident that you know what you’re doing. Just promise us that you won’t go out and steal SIM cards to use with your next project. Find part two of the tutorial here and keep your eyes open for future installments.

SIM Card Carrying Traffic Lights

January 28, 2011 by Mike Szczys 47 Comments

Apparently some of the traffic lights in Johannesburg, South Africa have SIM cards in them to help maintain the network without a physical connection. Now that’s some and not all, but apparently thieves have learned that the SIMs can be used in cell phones to make anonymous and unlimited calls. Officials are convinced that the thieves have inside information because they only crack open the lights that DO contain a card.

We’re white hats here at Hackaday and certainly don’t want to give out information that aids criminals. But since this is already a huge problem we have an idea of how thieves might be identifying which lights to rob. Sure, they probably do have inside information, but wouldn’t it be fairly simple to track down which lights use cellular communication by using a home made spectrum analyzer? We guess it would depend on how often the lights send out communications bursts. Does anyone have insight on this? Leave you thoughts in the comments.

[Thanks Bob]

Nokia Internet Key External Antenna

January 17, 2011 by Mike Szczys 13 Comments

[Maurizio] was having some reception issues with his wireless internet and set out to add an external antenna to the USB dongle (translated). He had previously poked around inside of the Nokia internet key to find that the internal antenna was a flexible circuit substrate wrapped around a plastic box that made contact with main circuit board via a spring connector. This plastic frame is just right for mounting an SMA connector in just the right place for it to stick out the end of the case as seen in the picture above. It gives him better range, but since speed depends on how much traffic the wireless node is under, it’s not a guarantee that you’ll get a snappier connection after this hack.

Cell Phone Endurance Tests

January 1, 2011 by Greg R. Jacobs 31 Comments

Gone are the days when a phone would last you a lifetime and enter the days of glass covered mobile phones built to be sexy and sophisticated. With these new phones come new testing methods. Companies like Nokia are still dedicated to making the best phones possible and making them durable through vigorous testing. The example shown in the article, is simulating a phone dropping from a shirt pocket onto the floor. Nokia claims to use 200 endurance tests encompassing temperature, extreme usage (use this button pusher for you own test), physical drops, and exposure to humidity on each new model in their product line. Makes one wonder what other companies are using for their endurance tests. There’s video of the Nokia N8 Drop Test is after the break, and don’t forget to leave a comment if you know about other interesting test methods.

Continue reading “Cell Phone Endurance Tests” →

GSM Hacking With Prepaid Phones

December 30, 2010 by Mike Szczys 32 Comments

Want to listen in on cellphone calls or intercept test messages? Well that’s a violation of someone else’s privacy so shame on you! But there are black-hats who want to do just that and it may not be quite as difficult as you think. This article sums up a method of using prepaid cellphones and some decryption technology to quickly gain access to all the communications on a cellular handset. Slides for the talk given at the Chaos Communications Congress by [Karsten Nohl] and [Sylvain Munaut] are available now, but here’s the gist. They reflashed some cheap phones with custom firmware to gain access to all of the data coming over the network. By sending carefully crafted ghost messages the target user doesn’t get notified that a text has been received, but the phone is indeed communicating with the network. That traffic is used to sniff out a general location and eventually to grab the session key. That key can be used to siphon off all network communications and then decrypt them quickly by using a 1 TB rainbow table. Not an easy process, but it’s a much simpler method than we would have suspected.

[Thanks Rob]