DIY Femtocell Hack Sniffs Out Malware on Mobile Phones

In last week’s edition, we highlighted a presentation at Black Hat Las Vegas by researchers who figured out how to hack a femtocell portable cellular base station in order to intercept all data transmitted by nearby mobile handsets. They informed device makers such as Verizon about the exploit so it could be remedied.

This week, Wired reported that the good guys have devised a method for using a femtocell to detect malware on mobile phones. In a presentation at the Def Con hacker conference in Las Vegas, researchers from LMG Security demonstrated a system they built for less than $300 that can view data transmitted from smartphones, through a femtocell, to a cellular carrier’s network. This allows a phone’s user to monitor his or her own data traffic for malicious activity.

“If your phone is infected … it can send audio recordings, copies of your text messages, and even intercept copies of your text messages so you never receive them,” LMG’s Sherri Davidoff told Wired. “Our goal is to give people the ability to see the network traffic” to determine if this is occurring.” The LMG jury rig not only allows traffic monitoring, says Wired, it also gives the user the ability “to stop the data from being passed to attackers from infected phones, alter it to feed the attackers false data, or pass commands back to the smart phone to remotely disable the malware.”

The researchers went a step further, releasing a paper describing their method that includes information so consumers can build the system as a DIY project. for others to use to develop their own system.