Electronic Listening Devices: The Art of Self Defence
Electronic listening devices are not easy to find.
IS there a relatively simple way to search for electronic listening devices? We’d like to implement procedures to create awareness without needing professional sweeps every few weeks in certain sensitive departments. Something else we’ve discussed is having a technical member of our team What would you recommend?
It’s a bit Man from U.N.C.L.E. but manual inspections are a good place to start. Have your team develop an awareness of tell-tale signs of electronic listening devices. Doing this properly means becoming familiar with certain common types of listening device. If you’re serious, you should buy some and use them for practice. Such devices might be obvious but in other cases the signs are likely to be subtle. A compact unfamiliar device plugged into an AC socket, a device with trailing wires or mini antenna in a location it shouldn’t be, such as under a desk or behind curtains.
The modern office does not make this process any easier, given the blue spaghetti of cabling and the mounds of legacy hardware many of us have laying around. Depending on the layout of the office environment it might be possible to see if phone sockets have been tampered with. Something else to take into account is devices residing on phone cables – these clamp around the wires and interpret electrical signals passing through the wires.
Some devices are almost entirely passive – they’re tiny – the size of the tip of your thumb, a few millimetres thick and incorporate a long-life lithium battery and a microSD slot of up to 128GB. These devices can be left in place and then collected later on – they don’t actively transmit/stream recordings. Such passivity makes them a special challenge for security teams.
The most challenging situation will be listening devices installed inside electronic equipment, or within common devices that serve a dual purpose, such as USB sticks, transformers or power boards. These will appear and may function no differently to the real thing, yet incorporate listening technology. For this reason, it can be simpler for organisations to have all sensitive meetings in designated clean rooms stripped of electronic devices and infrastructure, and regularly swept.
If you’re going to buy your own equipment and test for radio frequencies there are a few things to bear in mind. For a start, buy a unit with a quality aerial. In basic design this aerial will be connected to the top of a parallel tuned circuit that is resonant at the same frequency as the listening device’s transmitter.
This airy statement should be taken with a liberal dose of salt. The nature of covert surveillance devices is that their frequencies are unknown – this means the bandwidth of the tuned circuit of a radio transmission detector (essentially an antenna, a tuned circuit and a sensitive ammeter) needs to be wide. Because this is electronic security, there’s a caveat. The bandwidth can’t be too wide or the circuit loses sensitivity – it’s a juggling act.
When it comes to investing in detection devices there are plenty of options but you should make sure you speak to professional suppliers. At the top of the tree are products like the PRO7000FX, which covers digital and analogue devices and multiple bands, as well as having ultra-wide frequency response. The PRO7000FX will alert security teams to the smallest of transmission incidents, which is important.
There are plenty of other capable units that cost less than the 7000FX’s $A2500 but if you’re using the product regularly to protect the R&D or strategic planning of a serious organisation, make sure you don’t spend a few hundred bucks on a toy off the internet. Buy a quality product and learn how to use it properly with support from covert tech professionals.