How Hackers can Track your Mobile phone

How Hackers can Track your Mobile phone with a cheap setup

Cellular phones have become a ubiquitous means of communications with over 5 billion users worldwide in2010, of which 80% are GSM subscribers. Due to theiruse of the wireless medium and their mobile nature, thosephones listen to broadcast communications that could reveal their physical location to a passive adversary.

University of Minnesota researchers found a flaw in AT&T and T-Mobile cell towers that reveals the location of phone users. The attack, described in a Research paper (Click to Download Pdf), is most useful for determining whether a target is within a given geographic area as large as about 100 square kms or as small as one square kilometer. It can also be used to pinpoint a target's location but only when the attacker already knows the city, or part of a city, the person is in.

Ph.D. student Denis Foo Kune says, “Cell phone towers have to track cell phone subscribers to provide service efficiently. For example, an incoming voice call requires the network to locate that device so it can allocate the appropriate resources to handle the call. Your cell phone network has to at least loosely track your phone within large regions in order to make it easy to find it“.

The messages contain I.D. codes. In order to match the codes to the cell phone number, researchers called the phone three times. The code that appeared three times in the same time period in which researchers were listening in is most likely the code of the cell phone.“From there we can use that I.D. to determine if you’re around a certain area or if you’re on a particular cell tower,” he said.

The process requires a feature cellphone and a laptop, running the open-source Osmocom GSM firmware and software respectively, along with a cable connecting the two devices. It also uses a separate cellphone and landline.