GSM Wiretaps and Bugs – How to Fight Them?

A GSM wiretap (bugs/devices transmitting in GSM zone) is today one of the most common ways of spoiling your privacy. It is quite an inexpensive, very discreet, low maintenance and for the attacker safe method of interception. The cost-benefit ratio is (unfortunately for you) outstanding.

Miniature GSM bugs with multi-day battery life and voice control can be bought for around 45 US dollars. To install and to use such a device can any averagely technically skilled person and because of a great number of camouflaged and mini-sized designs it is almost impossible to find such device without professional equipment.

Why is GSM such as threat?

A GSM wiretap works similarly as other non-contact eavesdropping devices. It is a sensitive microphone placed into space that can transmit caught sound to the attacker.

Unlike some classic devices transmitting caught signal locally on a discreet frequency, the GSM bug uses already existing mobile network. It contains a regular SIM card that connects to the operator network through the closest base station (BTS) as any other cell phone would. This way it is able to overcome some of the usual limits of eavesdropping methods and also, it his harder to find.

Combination of a GSM bug and GPS knows of every step you take

Signal of a GSM wiretap cannot be tuned on to any ordinary (or specialized) receiver. Listening device usually works on the base of voice activation, combined with manual control. So basically, either the bug calls the phone of the attacker if it registers sound, or the attacker calls the bug that automatically accepts the call. And suddenly, your meeting has one more participant.

The biggest advantage of a GSM wiretap is its almost unlimited reach. Conventional bugs can transmit sound only to hundreds of meters distance, where is the receiver and the attacker or his/her recording device. To GSM you can connect from any place on earth as long as it is covered by mobile signal.

This method is therefore used not only for bugging households and offices, but also cars. To keep track of moving targets, GSM wiretap is usually combined with a GPS locator. The data is then sent to the attacker in a simple SMS, so he/she’s perfectly informed of the car’s movement.

GSM wiretap detection and defence

Unlike in case of inexpensive bugs transmitting signal on their own frequencies that can be detected quite easily, GSM wiretap detection can be very complicated. Amateurish methods or checks conducted by “private detectives” are usually useless. They can only give you the false impression that there is nothing to worry about which only helps the attacker.

A GSM wiretap cannot be detected by a radio scanner, a radio analyser or a VF detector. The only effective method fighting this kind of wiretap is a professional defensive technical check against wiretap during which a spectrum analyser is used. The analysis of a radio spectrum is along with a thorough manual check of the office, the household or the car an obvious part of the defensive check.

Acquired data are afterwards protocoled, evaluated and stored for later comparison. Thanks to them we can quickly and effectively detect new signals during our next visit. Our experts will then recommend suitable solutions for permanent protection of your privacy based on the results of the check.

You can fight GSM wiretap actively in two ways – using a white noise generator or using a GSM bug jammer. However, the use of the second one is in the Czech Republic and the EU illegal.