Police alerted politicians of the eavesdropping risk

Dec 15, 2014 23:35 GMT  ·  By
IMSI-catchers are the size of a computer and interpose between the client and the legitimate mobile tower
4 photos
   IMSI-catchers are the size of a computer and interpose between the client and the legitimate mobile tower

Fake mobile towers have been discovered in central Oslo, near buildings belonging to the Government as well as the Parliament, with the purpose of intercepting communication from mobile phones around them.

Also known as IMSI-catchers, these fake base stations function as man-in-the-middle (MitM) devices, are not detectable to regular phones because they act in a similar fashion to normal GSM equipment used for relaying information to other towers until it reaches the intended recipient of the communication.

The IMSI acronym comes from International Mobile Subscriber Identity, the only differences from regular towers being that they are smaller (the size of a computer) and have a shorter range, and they are handled without authorization, serving the purpose of eavesdropping on the interlocutors.

Norway authorities deny responsibility for the equipment

According to Aftenposten, which carried out a two-month investigation (from October 10 until November 21) in order to find the fake base stations, this is clearly expensive equipment that cannot be sold legally to private individuals, especially in NATO member countries.

The publication says that in Norway only the Police Security Service and the National Security Authority are authorized to use this type of equipment, but officials of the two organizations have denied that it belongs to them.

The journalists relied on CryptoPhone, which can analyze suspicious activity in the baseband processor of the mobile phone, to identify suspicious activity indicative of IMSI-catchers.

Once they were sure of the eavesdropping activity, they worked with two security companies that provided more accurate equipment for closing in on the fake base stations. However, in order to accurately pinpoint their position, authorization from the police and access to the premises was required.

Fake towers positioned in area with highly important government institutions

In Oslo, important government buildings are located within a radius of one kilometer, which is also the reach of the IMSI-catchers, if no constructions are in the way. In places with buildings, their capturing functions extend over a shorter distance.

In the area of particular interest to the operators of the fake towers, there is the office of the Prime Minister, the Ministry of Defense, and the Parliament, as well as the central bank of Norway, Norges Bank.

It is safe to assume that the equipment is part of a cyber-espionage mission targeting high-profile officials in the country, but the identity of the operators behind the campaign remains a mystery at the moment.

The price of these base stations has been determined to be between $85,000 / €68,000 and $330,000 / €265,000, it can be assumed that foreign intelligence may be behind the operation. However, no theories have been issued and the actors can very well be private companies, as well as cybercriminals gathering intelligence.

An official investigation from the National Security Authority in Norway has been initiated to find information about the operators of the equipment and their function in the area.

IMSI-catchers in Oslo (4 Images)

IMSI-catchers are the size of a computer and interpose between the client and the legitimate mobile tower
Norwegian Parliament building in OsloNorway Prime Minister, Erna Solberg
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