Protecting Against Drones: A Brief Review of Passive Countermeasures

Protecting Against Drones: A Brief Review of Passive Countermeasures

“OK, I detect a drone that’s flying over my facility — now what?”

That’s one of the more common questions people ask about drone-based threats, regardless of their line of work. At first, some assume that the next step is to somehow take the drone out of the air — perhaps by jamming or capturing it — but these active countermeasures usually aren’t legal and may not be practical. Contrary to active countermeasures, passive countermeasures are completely legal, and they’re also extremely effective and reliable  — so it’s no surprise they’re the most popular tools used to protect against drone-based threats. Below is a short overview of passive countermeasures grouped by the types of threats they mitigate.


Spying drones take advantage of powerful photo and video equipment to record sensitive things such as attendees in executive meeting rooms, facilities or equipment (particularly those that might contain intellectual property), or people (e.g., invading their privacy). In these cases, the most effective countermeasures are often ones that simply shield those sensitive things from the drone’s spying cameras. This could mean:

  • Closing windows shades or blinds so the drone has nothing to photograph except a blank window (optionally this can be done remotely or automatically via a building management or automation system, a BAM/BAS)
  • Leading people inside and away from open areas, or away from large windows or areas where a drone might have clear line of sight — this is especially useful when protecting events such as sensitive meetings with 3rd parties
  • Hiding sensitive equipment or activities by using high-powered floodlights (that essentially overpower the drone’s camera sensor), deploying smoke clouds (aka fog bombs), or covering sensitive equipment with fabric or portable shading/tents
Concealing a sensitive object can be surprisingly effective against a drone’s spying camera


With the ability to lift many pounds of payload, drones can easily carry hacking-capable devices, such as small on-board computers (e.g., a Raspberry Pi), WiFi/Bluetooth dongles (used to find vulnerabilities in networks, infrastructure, or devices), or radio transceivers (used to transmit data back to the pilot). As with more typical cybersecurity threats, it’s important to carefully monitor the network and infrastructure for anomalies, and possibly do one or more of the following:

  • Monitor the wireless and wired Ethernet network for intrusions, or rogue / spoofing wireless networks (SSIDs)
  • Review access logs to search for unauthorized access
  • Temporarily turn off the guest wireless network
  • Send physical security staff outside to patrol the facility, searching for dropped contraband or the drone itself (if it landed)‍


With the ability to carry many pounds, drones can deliver a payload somewhere inside a protected facility. Organizations using tools such as Dedrone’s video detection technology can track the drone’s flight in real-time, and those that have robust security camera coverage of their facility in place can simultaneously monitor video feeds to watch the drone deliver its payload. Physical security staff can be dispatched to investigate and retrieve any dropped items, or simply signal to the pilot that the drone has been spotted.

To successfully use countermeasures to protect against unauthorized drones, one must first detect and locate it, ideally tracking its flight path precisely. Once a drone is detected, one or more of the above countermeasures are executed depending on the nature of the threat and the particulars of the protected facility/organization. In all of the above cases it’s also important to integrate counter-drone security measures into existing security programs, including physical staff procedures and IT security. If you’d like to learn more about integrating drone detection and countermeasures into your security program, contact us to discuss your specific needs.


By Pablo Estrada

Published with permission from