TSCM Explained

What is a Technical Bug Sweep?

A Technical Surveillance Countermeasure (TSCM) is also known as a bug sweep, de-bugging, or electronic surveillance sweep. A highly advanced service that can detect the presence of hidden eavesdropping devices such as ‘bugs’, microphones, video, and location tracking devices. The goal of a sweep is to identify existing security breaches and to provide corrective actions to eradicate potential flaws in technical and communications security.


Who needs a Sweep?


The most common reason is an executive or company is involved in matters that require a higher level of security where information loss could prove very costly. Another reason for TSCM could be that you have a suspicion that someone is trying to spy on you. This could be a jealous partner, someone from your past, or even someone who simply holds a grudge against you, your business, or something else that you represent.


High Threat Situations


  • Key executive leaving
  • New products or pricing are being developed
  • Acquisitions or mergers are being planned
  • Work occurs in a sensitive or high-profile industry
  • Executives or clients are subject to media attention
  • Any type of litigation, lawsuit, or other civil action is occurring.
  • Impending termination of employees

Types of bugs


GSM bugs – Perhaps the prolific listening device today, GSM bugs operate in exactly the same way as a mobile phone and a perpetrator can in effect, dial in and silently listen to a conversation from anywhere in the world. A GSM bug can be a small black box that can be discreetly hidden in a room or it can be a purpose built device such as a mains adaptor, a power strip adaptor, a PC mouse or a phone charger for example. These are everyday objects that one would expect to find in an office, for example, but which could harbour a dangerous secret! High quality GSM bugs are readily available to buy online and from some high street shops and prices start from under $10


Miniature Voice Recorders – Readily available from online stores, miniature recording devices such as Edic-mini recording devices and those disguised as USB drives or credit cards are discreet audio recording devices designed to be easily hidden or pass undetected by the unwary target. Their use is limited by their battery life and storage, but in many situations they can be just the weapon an infiltrator needs while being affordable and delivering high quality audio.


A Radio Frequency (RF) – These bugs involve the placing of a radio transmitter in a room and listening within range using a receiver. Radio frequencies are given off by nearly all spying devices, and these radio frequencies can be detected with specialist equipment as used by TSCM engineers.  Different types of bugs give off a large range of frequencies and specialist equipment is required to check the entire RF spectrum.  Basic RF detectors, that can be purchased relatively cheaply, will only be able to detect limited frequencies and will give you a false sense of security, and so its always best to engage the services of a TSCM firm.


Tap or Wiretap – This is a device placed on the telephone system and is designed to intercept telephone conversations, i.e. if no call is in place then the tap is inactive.


Telephone bug – used to listen to room conversation but may use the telephone or line as a facilitator of this. This type of attack means that all conversation in the area is susceptible to being overheard by the attacker and not just telephone calls.


Optical devices – They convert audio signals into transmitted light pulses which are then converted back to audio signals by a receiver. One example of this is the laser attack whereby a laser beam is projected onto a surface, such as a window, and the vibrations detected are converted into audio signals. Laser attacks are difficult and expensive to conduct.


Equipment Used

  • Spectrum Analyzers – For more advanced analysis of threatening and non-threatening signals
  • Nonlinear junction detectors – Detecting components associated with hidden eavesdropping devices.
  • Multimeters – Measuring power supply and device components for anomalies
  • Time-Domain reflectors – Testing the integrity of copper telephone lines and internet cables
  • Frequency scanners – Checking electromagnetic spectrum for ‘unexplained’ signals
  • Thermal imaging Device – To identify concealed ‘active’ or warm devices.
  • General use tools – Ladders, Flashlights, Hammers, crowbars, video camera on a pole, lighted mirrors on poles.

Modern TSCM


TSCM used to be about sweeping rooms for listening devices using technology that can detect radio wave emissions. Now non-radio emissions can also be detected – Magnetic waves, Light emissions, thermal emissions, and a typical sweep also involves securing communications technology and fortifying security protocols to prevent future espionage. Modern surveillance devices are smaller, very capable, and more hidden. Bugs can be found in USB Cables, light bulbs, clocks, books, walls, sockets and smoke alarms, these devices can be much more easily purchased by anyone online, nation state devices are even smaller, more powerful, and harder to detect. Devices can ‘lie dormant’ to evade normal detection.

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