In the process of functioning of computer equipment, technical channels of information leakage arise. Today, the list of technical channels of information leakage, as well as methods and means to combat leaks through these technical channels are regulated by the current regulatory documentation in the field of technical information protection. However, it turns out that there are also a number of technical channels of information leakage, measures to counteract which are not provided for by the current regulatory documents in the field of technical information protection. For the sake of brevity, this type of technical information leakage channels is called hidden technical information leakage channels. Examples of hidden technical channels of information leakage used to transmit data processed in a computer tool are: - power lines in which the dependence of electricity consumption on time is determined by the load of the central processing units (CPUs) of the computer tool, controlled by a pre-installed special program; - acoustic ultrasonic channel formed by passive speakers and headphones without using a microphone; - low-frequency magnetic vibrations that occur during the operation of the CPU of computer equipment; - radio emission that accompanies the process of entering information on a smartphone, which is recorded and analyzed on the intruder's smartphone using an FM tuner; - variations of thermal radiation of the computer equipment housing; - acoustic radiation generated by disk drives in the process of writing and reading information; - electromagnetic radiation that occurs during access to various devices via the USB port; - optical radiation of led indicators means of computing technology, etc. Taking into account the real danger of unauthorized access to data processed in a computer tool, it is clear that there is a need for scientific research of hidden technical channels of information leakage in order to develop methods for assessing threats to information security and develop scientifically based methods and means of protection against information leakage using these technical channels of information leakage. The article reviews open scientific publications devoted to the research of hidden technical channels of information leakage, including the mechanisms of information transmission through hidden technical channels of information leakage and experimental results confirming the operability of these mechanisms.