How Hackers Can Track Your Smart or Prepaid Phone

 Smart Phone are means of communications with over 5 billion users worldwide in 2010. About 80 of those are GSM subscribers. Hackers can listen to broadcast communications that could reveal your physical location to a passive adversary. Some researchers found a flaw in AT&T and T-Mobile cell towers that reveals the location of phone users. They can determine
whether a target is within a given geographic area as large as about 100 square km's 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. 


Location Leaks on the GSM Air Interface. A GSM cellular network is composed of 15 main logical
entries. The entries relevant to this work are as follows: The Visitor Location Register (VLR), The Base Station System (BSS), and The Mobile Station (MS.For More Information on the attack and how they attack check out this link: http://www-users.cs.umn.edu/~foo/research/docs/fookune_ndss_gsm.pdf

Cell phone towers have to track cell phone subscribers to provide service efficiently. 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 you can use the I.D. to determine if you’re around a certain area or if you’re on a particular cell tower.

 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 land-line. The equipment and use the laptop output to monitor the broadcasts that immediately follow over the airwaves to page the target phone.