As you know, there are thousands of Bluetooth and WiFi signals we pass through daily, especially if we live an active life in a big city. That includes tags, smartphones, WiFi routers, drones, surveillance devices, vehicles, body cams and mesh radios. Clearly it doesn’t stop here and the list goes on.
Many of you are privacy focused individuals and want to know what’s going on around you and whether you’re being tracked or watched by someone. That’s okay, protecting your privacy is a good thing. FieldWatch was made for this. It matches what it hears against an editable signature catalog of roughly 250 device types and shows the results in live views, recorded sessions, path maps and reports. Everything runs on the device and works fully offline.
FieldWatch
FieldWatch is a free, open-source Android app that listens to nearby Wi-Fi and Bluetooth signals using the radios already in your phone. It compares what it hears against a list of known device signatures and shows them. It only receives signals. It never transmits.
Source: OGridPeteSource: OGridPete
You can set alerts for specific devices, record what’s present during a walk or drive, and later compare sessions. All the findings are sorted under their category. It also has basic GNSS interference detection and can send results to mapping tools like TAK. Matches are based on patterns, not guaranteed identifications, and the app only sees what the phone’s radios and Android allow it to see.
Depending on your preferences, you may want to see these devices on a radar or on a map. The app found the location of the drone operator as well as the drone itself.
Source: OGridPeteSource: OGridPete
TAK Support
TAK and ATAK are free mapping apps used by military, emergency responders and some civilians to share locations and information on a map in real time. FieldWatch can send what it detects straight to TAK over the local network.
When FieldWatch sees a drone that’s broadcasting Remote ID, it can place a moving marker on the TAK map for the drone and a second marker for the pilot if that location is available. Other devices it finds, plus any GNSS interference alerts, can also appear as markers. Several phones running FieldWatch can send data to the same map at the same time, so a team sees the same picture.
Source: OGridPete
GNSS Interference Detection
Newer versions check for signs of GPS interference or spoofing using the phone’s own receiver. After a short outdoor calibration, it can alert you and mark the spot on your path or on a TAK map. It shows where you were, not where the interference came from.
Source: OGridPete
Limits
Now let’s talk about its limits. It isn’t a direction finder. Also, it doesn’t scan Bluetooth Classic, cellular networks or full Wi-Fi traffic. Matches are based on patterns and those are not confirmed identities. Your results depend on the phone and what Android lets the app see. For better results use newer phones. Official versions only come from the GitHub repo.
Android App
Download the APK from the official GitHub page and sideload it. Android 10 or newer is required. Android 11 has more functions that can be used with this app. A short instruction file and manual are included. The repository has all the answers in terms of the app. It works on a cheap phone with no SIM card. OffGridPete recently posted that he used a Moto G for $30 for his test and it worked well. If you decide to use it, use it for your own privacy and security, and be respectful of other people’s privacy.
Summary
You can use your cheap phone as a scanner for devices nearby, and find jamming and tracking. There are different apps that do similar things, but they’re bound to Linux only, which is very inconvenient. FieldWatch works on an Android phone to find trackers, cameras, drones, body cams and more.
If you enjoy experimenting with frequencies and trying new things, we recommend signing up for our SDR for Hackers training. With Master OTW, you’ll learn how to use your computer and inexpensive SDR hardware to explore and hack a wide range of radio signals.
Many beginners want to know how they can hack their Wi-Fi. It’s fun, it’s easy to get started with and those small wins make the early part of your cybersecurity journey exciting. Testing Wi-Fi security is also an important part of a pentest, since many organizations keep old routers in place with weak security settings. As years go by, those settings get more and more obsolete, like WEP. Some features routers have enabled by default might be convenient, but are often unnecessary. That’s WPS, as you might know. It gets abused regularly to recover a plaintext password and sometimes you can get it in under a minute just because WPS was left on.
If hackers get onto the network, they can start exploring everything on it or just use your Wi-Fi for their own purposes. You don’t want that. That’s why you need to make sure it’s secure.
Today we’ll cover Wifit3, which can help you with this.
What is Wifit3
The tool was developed by the same author who created Wifite2.
Unlike its predecessor, it doesn’t need aircrack-ng, reaver or bully installed. Instead, it uses pure Python with the PyUSB and Textual libraries. Wifit3 works just as well on Linux, macOS and Windows. You’ll only need a USB dongle to work with it. The repository mentions all the supported devices.
It scans both 2.4 GHz and 5 GHz, can tell when a network is WPA3 or in mixed WPA2/WPA3 mode and keeps track of signal and encryption. It also tries to identify the router and pull extra details about it. Hidden network names sometimes get revealed by matching them to a known router address. If you plug in more than one supported Wi‑Fi adapter, you can listen on several at once and leave one free to send packets.
It shows beacons, data, injection and disconnect traffic so you can see what’s in the air while you work.
The tool can listen to Wi‑Fi traffic and send disconnect messages. Those messages kick phones off the network. When a phone joins again, it talks to the router to prove it knows the password. The tool records that conversation. The password is in there, but scrambled, so you can crack it later with hashcat.
Here’s how it looks. Above you can see it capturing handshakes with passwords after disconnecting a client. The tool also managed to capture a PMKID. PMKID is a short hash the router can send that’s tied to the Wi-Fi password. If you capture that hash, you can try passwords against it later on your own machine. You don’t need to kick anyone off the network or capture a full login handshake.
There’s also an Evil Twin mode for WPA3. It tricks phones into leaving the real Wi‑Fi and joining a fake one so the tool can steal a handshake. For WPS it can try the fast Pixie Dust attack, grab the password when someone presses the router’s WPS button and keep guessing the WPS PIN while pausing if the router starts locking out attempts.
That’s how the WPS attack looks. The tool sends an enrollee identity with a public key and gets the router credentials decrypted. The password is then saved to a text file.
WEP is attacked in Python with the usual replay tricks to recover the key.
Setting Up
Now let’s set it up on our machine. As always, we’re going to use Kali, but you can use anything you want.
kali > wget https://github.com/derv82/wifit3/releases/download/v0.3.2/wifit3-linux-x64 -q
kali > chmod 777 wifit3-linux-x64
kali > mv wifit3-linux-x64 wifit3
kali > sudo cp wifit3 /usr/local/bin
We’re all set. Plug in your USB dongle and start the tool.
kali > wifit3
After choosing the right, you can start testing your Wi-Fi. Use it only on your own Wi-Fi or the one you’re authorized to test.
Summary
There are so many vulnerable Wi-Fi networks you’ll come across during pentests. They’re often the quickest way into a network, which is why their security shouldn’t be overlooked. Wifit3 is a new tool that came out relatively recently. It’s easy to work with and can help you cover all the common wireless attacks.
If you’re interested in Wi-Fi security, our Wi-Fi Hacking training can help you gain the necessary experience.
Take a second and think about how many devices are actually working around you right now. Cameras on street corners, routers sitting inside nearby homes, Bluetooth earbuds in someone’s pocket, cell towers just outside of view. All of that is happening constantly, yet almost none of it is visible to the average person walking by. If you actually wanted to check what devices were nearby today, you would probably end up jumping from one app to another, waiting for each one to load, and still walking away without the full picture. It is slow, it is frustrating, and honestly, it takes all the fun out of exploring what is really going on around you.
A lot of these devices are not just sitting there minding their own business. Many of them are built specifically to track you. A recent video on X showed this. It captured a flock camera taking several pictures of a moving vehicle, running those pictures through some kind of analysis, and then filing everything away in an indexed format.
In the screenshot above, you can see the guy picking up the signal coming straight off the camera, while the camera itself keeps emitting a steady beam of infrared. Here is the full video.
Privacy is not a crime, and you have every right to know what might be watching you. The real challenge has always been figuring out where all of these surveillance devices are hiding. That’s where WireTapper can help us. It pulls data from Wigle, Shodan, and OpenCelliD one at a time. That way, you can see every one of these devices in your area.
WireTapper
WireTapper is a wireless OSINT tool designed to discover, map, and analyze radio based devices using passive signal intelligence. WireTapper detects and correlates signals coming from all the common wireless technologies you would expect to run into. This helps you understand what devices actually exist nearby and where they are likely located all without ever having to actively intrude on anything.
WireTapper can identify leaked Wi-Fi network credentials, and it does this through a privacy-protecting k-Anonymity query scheme, meaning it can check for exposed passwords without ever exposing your own search to the outside world.
Setting Up
Let’s quickly walk through the installation process. It’s a lot simpler than it looks.
kali > git clone https://github.com/h9zdev/WireTapper.git
kali > cd WireTapper
kali > python3 -m venv venv; source venv/bin/activate
kali > pip3 install -r WireTapper.txt
Once that finishes, you will need to grab API keys from each of the services mentioned above. Do not worry too much about Shodan, since its API is paid and WireTapper will still run fine without it. There are two ways to plug these keys into the app. You can either open app.py and enter them directly, or you can use app-env.py instead, which pulls the keys in through environment variables.
After you have picked your method, we recommend also installing python-dotenv, since it makes handling those environment variables a lot smoother.
kali > pip3 install python-dotenv
Working with WireTapper
Once everything is installed, you are ready to start the app and open the web interface.
kali > python3 app.py
The web interface will be waiting for you right here: http://localhost:8080/map-w
This is the dashboard you will land on the moment you open the page. It takes a little while to load everything, so give it a few minutes before you start clicking around. Once it settles in, you can zoom into whatever area you are curious about and start picking apart what is actually hiding there.
Just keep in mind that you need valid API keys for the app to work the way it is meant to. Without them, WireTapper will simply generate dummy data so you can still see how everything normally looks inside it. On Wigle specifically, your email needs to be verified before the connection will work properly.
At the top of the dashboard, you will notice a switch that lets you jump between Wi-Fi uplink and Bluetooth scanners. That is how you filter what you are looking at.
Flip the switch back the other way, and you get the same kind of view but for Wi-Fi devices instead. This side usually includes things like cameras, routers, and other similar devices.
Exporting Results
All of these results can be exported complete with their names and coordinates, in case you decide to use them somewhere else later on.
The example above is just a taste of how those exported results are going to look. You can use this JSON file with other tools.
Summary
There is far more happening around us than most people realize. WireTapper makes it easier to visualize that activity by bringing together information about nearby wireless infrastructure in one interface. If you’re into OSINT, privacy, or wireless security, it’s a handy tool.
OSINT is a valuable skill in many areas, especially when it comes to privacy, cybersecurity, and cyber warfare. The more you understand what information is publicly exposed, the better you can protect yourself and your digital assets. Our Ultimate OSINT Beginner training covers OPSEC, tracking, investigations, and much more across 23 lessons and 7.5 hours of video content.
We’re also hosting a live Remaining Anonymous training on August 11-13 at 3:00 PM UTC for all Subscriber and Subscriber Pro students.
Lately, we’ve covered several tools you can use with your laptop to track nearby devices and people. While they’re useful, their effectiveness depends on the strength of your Bluetooth adapter, and, of course, you need to have your laptop with you.
This time, we’re doing things differently. We want to show you a device that can automatically monitor nearby devices for extended periods, anywhere you choose to place it, and as often as you want. It doesn’t rely solely on Bluetooth, as it also uses Wi-Fi, which is far more likely to be enabled, increasing the chances of detecting someone in your area.
What is Paxcounter
Paxcounter is an open-source firmware project that takes a cheap little ESP32 development board and turns it into a sensor that can count people. Almost every smartphone in the world is constantly sending out small Wi-Fi signals, called probe requests, and Bluetooth signals too, even when the phone is not connected to anything. Paxcounter listens for these signals in the air. It counts how many different devices it hears during each scan, and from that, it can tell you a real time estimate of how many people are nearby.
The project started out as a simple way to measure how many passengers or pedestrians pass through a certain spot. But over time, it grew into something much bigger. Now it works as a general purpose IoT platform, built on hardware that usually costs somewhere between $10 and $30. Besides its main job of counting Wi-Fi and Bluetooth devices, a Paxcounter can also read environmental sensors, track its GPS position, keep accurate time, and send all of that data out through LoRaWAN, MQTT, a local serial connection, or straight onto an SD card.
How the Counting Works
The way Paxcounter counts people is simple, but it was clearly built with privacy in mind from the very start. Every scan cycle, which lasts 60 seconds by default, the device switches its Wi-Fi and Bluetooth radios into scanning mode and listens for probe requests and advertisement packets coming from nearby devices. Each of these packets carries a MAC address. Paxcounter takes just the last two bytes of that address and turns them into a short, temporary ID. This ID is only used to check for duplicates during that one scan cycle. Once the cycle ends, the count of unique IDs gets sent out, and the whole list is wiped from memory. The firmware also does not try to fingerprint any device. It never tries to figure out a phone’s brand, its operating system, or who owns it. All it wants to know is whether that device has already been counted in the current window.
This scan and clear cycle just keeps repeating, either nonstop or on a schedule if deep sleep power saving is turned on. The results, which include the Wi-Fi count, the Bluetooth count, and sometimes live sensor readings too, get packed into a small payload and sent out through whatever channel the device is set up to use. One thing worth knowing is that Wi-Fi and Bluetooth scanning actually share the same 2.4 GHz radio hardware on the ESP32. So running both scans at the same time slightly lowers the accuracy of each one. Because of that, the project’s own advice is to split Wi-Fi only counting and Bluetooth only counting across two separate devices whenever the best possible accuracy is needed for both.
One Firmware, Many Boards
Paxcounter comes with a hardware abstraction layer and its own pin mapping files for dozens of ESP32 and ESP32-S3 boards. These come from well known manufacturers like LILYGO and TTGO, Heltec, Pycom, WeMos, M5Stack, and Adafruit, and there is also a generic template ready for boards that are not officially supported yet. LILYGO even sells a ready-made board called Paxcounter LoRa, built specifically to run this firmware.
Depending on which board you pick, your device can end up supporting a LoRaWAN radio for sending data over long distances while using very little power, an OLED status screen, or a single color, RGB, or larger LED matrix light to show status. It can also support a physical button for flipping through display pages or sending an alarm message, battery voltage monitoring, GPS positioning, a real time clock chip along with IF482 or DCF77 time telegram output, and even an SD card slot for logging data locally when there is no network around.
Because the whole system was designed to be truly portable, the documentation goes into real detail about power draw, which usually sits somewhere between 450 and 1000 milliwatts depending on how the device is set up. It also makes good use of the ESP32’s deep sleep mode, so a device can keep running for a long stretch of time on just one 18650 lithium ion battery cell. Members of the community have already shared several 3D printable enclosure designs on Thingiverse for the more popular boards.
Getting the Device Up and Running
Paxcounter is built using PlatformIO instead of the plain Arduino IDE. This choice lets it work smoothly with editors like Visual Studio Code, Atom, or Eclipse, and it gives the project reproducible, script driven builds. In fact, the repository runs an automated PlatformIO build check every single time the code changes, using GitHub Actions, and there is even a CodeFactor badge that keeps an eye on ongoing code quality.
The configuration is intentionally spread across a handful of different files instead of being crammed into just one. This keeps board specific settings, behavioral settings, and personal settings nicely separated from each other. The platformio.ini file is where you select which board’s hardware profile you want to compile against. The paxcounter.conf file handles behavioral settings, things like how long a scan cycle lasts, sleep timing, and payload options. The shared lmic_config.h file sets the LoRaWAN region and frequency plan, so it matches the rules where you live. The shared loraconf.h file holds the device’s LoRaWAN join credentials, and the project recommends using OTAA rather than ABP for this. And the shared ota.conf file stores the Wi-Fi credentials the device uses for over the air firmware updates.
You can upload firmware the traditional way, over USB, or once a device has joined a LoRaWAN network, you can push updates over the air instead. A remote command tells the board to connect to Wi-Fi, check a hosted repository called PAX.express for a newer build, and then download and flash it automatically. If anything goes wrong during that process, it will roll back to the previous version on its own. Devices can also be set up to open a small local web based bootstrap menu right when they power on, which lets you upload a firmware file manually, even from a phone in tethering mode, without needing PlatformIO installed on site.
Configuration and Extensibility
Beyond just picking a board, Paxcounter gives you a long list of settings you can tune to fit your needs. It can log environmental data from sensors like the Bosch BMP180, BME280, BMP280, or BME680, read a Nova SDS011 particulate matter sensor to track dust in the air, and keep accurate time using either a DS3231 real time clock or a connected GPS module.
Display and LED
On boards that come with an OLED display, Paxcounter shows live status information you can cycle through with a short press of the button. This includes the current pax count, meaning the people count, a histogram of recent activity, GPS status, environmental sensor readings, and the time of day.
A long press of that same button sends an alarm message out over the network instead, which is a simple way to flag a problem from out in the field without needing any other kind of interface. Even on boards that do not have a display at all, a status LED still tells you what the device is doing through its blink pattern. You get a brief flash whenever a new Wi-Fi or Bluetooth device is spotted, a quick blink while the device is joining the LoRaWAN network, a short blink during data transmission, and a slow, long blink if there is a LoRaWAN stack error. Boards that have an RGB LED get a color coded version of these same signals.
How You Receive the Data
Once a Paxcounter has counted the people nearby and packed everything into a message, that data has to go somewhere so you can actually see it. How that happens depends on which output the device is using, and the good news is you can turn on more than one at the same time. If you are using LoRaWAN, which is the most common setup, the device does not send the data straight to you. Instead, a nearby LoRaWAN gateway picks up the signal first and forwards it on to a network server, usually The Things Stack. There is a small decoder script included with the project, and its job is to take that raw message and turn it into numbers you can actually read, something like a pax count of 14. From there, The Things Stack can pass the data along to your own app or dashboard using MQTT or a webhook, or you can simply watch it come in live through the built in console.
If a board does not have LoRa hardware built in, it can just skip the gateway completely and send that same kind of data straight to an MQTT service over Wi-Fi instead. You can also connect the device to a computer using a USB cable and read the numbers directly from a serial connection. This is a simple way to test things out without needing to set up a network at all. If SD card logging is turned on, everything also gets saved locally as a CSV file, so you can pull the card out later and open it up in a spreadsheet. This comes in handy in places where there is no network coverage to rely on.
Where It’s Used
Because a single Paxcounter device is cheap to build and can be left running unattended for a long time, you will find it popping up in a pretty wide range of places. Retailers and shopping centers use it to measure foot traffic without needing to install cameras. Event organizers use it to watch how crowds move around a venue in real time. Pentesters can get a passive read on how many Wi-Fi and Bluetooth devices are active in a building, or to notice unexpected devices showing up where they shouldn’t, all without needing camera access or network credentials.
Legal and Privacy Considerations
Since Paxcounter’s whole job involves listening to wireless traffic, its documentation is unusually upfront about the legal side of things. It points out that sniffing Wi-Fi and Bluetooth MAC addresses may be regulated or restricted depending on where you live, and it links to specific starting references for the US, the UK, the Netherlands and the EU, and Germany. It also makes clear that the legal responsibility for how a device is built and deployed falls on the person doing it, especially for public deployments where the results might get published somewhere. On the technical side of privacy, the project’s own design actually holds up pretty well against that legal backdrop. Identifiers are only ever built from the last two bytes of a scanned MAC address, they are kept in memory just for the length of one scan cycle, and then they are discarded completely. No MAC addresses or identifiers are ever sent out over the network, and the firmware does not do any extra tracking or fingerprinting of the devices it scans.
Summary
What really makes Paxcounter stand out is not any single feature on its own. It is the whole combination working together. One piece of open source firmware supports dozens of cheap boards, runs for a long time on a small battery, counts people without saving anything identifying about them, doubles as a general environmental sensor node, speaks LoRaWAN, MQTT, serial, and SD card all at once, and can be fully reconfigured from a distance once it is out in the field. The full source code, the complete board list, and all the documentation are available on GitHub.
If you enjoy experimenting with frequencies and trying new things, we recommend signing up for our SDR for Hackers training. With Master OTW, you’ll learn how to use your computer and inexpensive SDR hardware to explore and hack a wide range of radio signals.
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