Cell Phones used as Listening Devices

A recent article in CNET highlights a new privacy threat posed by cell phones: Their microphone can be enabled, even while the phone is “off,” allowing an eavesdropper to listen to conversations held within listening distance of the phone. The FBI recently used this “roving bug” as one method of electronic surveillance while investigating the Genovese organized crime family in New York.


Although there is some conjecture on exactly how the “bugs” worked, it’s been generally agreed that rather than installed a physical device — which may have been impossible in the Genovese investigation — the cell phone carrier, Nextel in this case, may have remotely installed software causing the phone to call an FBI number where the “open mic” could be recorded while the phone’s display still indicated it was off-hook and offline. This theory is supported by the fact that the affidavit requesting the court order for electronic surveillance included the phone number, the 15-digit IMSI (International Mobile Subscriber Identifier), and the name of the carrier for the cell phone they wanted to bug. This information would not have been necessary if a physical bug had been used.

This is not the first time ordinary cell phones may have been used for surveillance. A 2004 BBC article suggests that this method was used by US and British security agencies to routinely bug senior UN officials, including the Secretary General, Kofi Annan.

As a privacy issue, there may not by any immediate cause for alarm. This method of surveillance requires the cooperation of cell phone providers, so it is currently only useful as an eavesdropping tool for government agencies — which, by itself, may or may not be cause for concern. However, since this is simply an application of software, it’s probably only a matter of time before hackers or virus writers make this a much more common occurrence.

If your job requires to you discuss very sensitive or top secret information, it might be best to go ahead and remove your cell phone battery for the duration of the meeting.

Link: CNET: FBI taps cell phone mic as eavesdropping tool
Link: BBC: ‘This goes no further…’

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