Transcript

Please excuse any grammatical errors. I used a tool to generate the transcript and haven’t had a chance to read through it yet.

Two weeks ago, Ben Jordan released a video covering a bunch of really cool tech, including the EFF’s Ray Hunter project. I will give a quick summary here, but I also wanted to make a step by step video showing how to install this on Windows, macOS, and Linux, mostly just to show how easy it is.

At the time of recording this, you can build one of these for between $25 and $40. But before we set anything up, let’s talk about why this thing exists.

Every phone has something called an IMSI, an International Mobile Subscriber Identity. It is basically a unique ID tied to your cellular connection. Normally, when your phone connects to a network, that ID gets shared as part of the authentication process. That information is supposed to be gated behind warrants, probable cause, and the Fourth Amendment.

But that is inconvenient if your job involves detaining people who have not actually committed crimes. So instead, the highest funded federal law enforcement agency in the United States, ICE, spends taxpayer money on fake cell towers.

These devices, also known as IMSI catchers, impersonate legitimate cellular networks. Your phone automatically connects because that is how cellular standards work. Once that happens, ICE is not just collecting identifiers and location data from their so called target. They are collecting it from everyone nearby.

To make this kind of surveillance easier, these devices often force phones onto weaker, older protocols like 4G, 3G, or even 2G, where protections are worse or basically non existent. If you ever notice your phone suddenly dropping to an older network in a dense urban area where 5G is normally available, that can be a red flag.

If you or I tried this, we would be committing multiple felonies. When ICE does it, they call it enforcement. And because oversight is optional and accountability is rare, the burden shifts to the public to notice when it is happening.

That is where this device comes in.

Using cheap, discarded cellular hotspots and open source firmware from the EFF, we can turn throwaway hardware into portable IMSI catcher detectors. Before we begin, there is a legal disclaimer, so make sure you read that before continuing.

To be clear about what this device actually does, it is essentially performing a packet capture with a set of rules that look for specific patterns. When one of those patterns is detected, it generates an alert and logs it for later analysis.

I want to be very clear that just because an alert is generated does not mean an IMSI catcher was present. It simply means something unusual happened and it is worth taking a closer look. Likewise, just because you do not get any alerts does not mean everything is perfectly normal.

One more thing to note is that this device needs a SIM card inserted to work, but it does not have to be active. I am using a two dollar Mint Mobile SIM I picked up at Best Buy a couple of years ago. You can also find them at places like CVS or Walgreens. Any SIM card should work.

Because this device uses a SIM, it does transmit an IMSI of its own, so it is not completely invisible. That IMSI could be logged by a carrier or by an IMSI catcher if you happen to encounter one. That said, this SIM is not meaningfully tied to you. There is no active plan, no billing information, and no name attached to it.

Realistically, if you are carrying this device around, your phone is probably nearby or sitting right next to you, and that is by far the bigger privacy risk.

For this video, I will be using the Verizon Orbit RC400L. If you do not live in the United States, there are other supported devices that work in other countries.

If you are not here for the installation, you can skip to the last part of the video to see a demonstration of the interface. If you are here for the installation, the first few steps are the same regardless of which operating system you are using, so we will start there.

Device Setup

Here is my device. The first step is to insert the SIM card. One of the corners has a notch cut out. You can usually slip a fingernail in there, but if it is your first time removing the cover, it can be a little difficult. You may want to use something plastic, like a butter knife, to pry it off.

Once you get it started, just pull and the cover will come off.

On the back, you will see the battery. I miss the days of removable batteries. Pry it up and take it out. I am blocking part of this so you cannot see the details of my device.

The SIM card goes in the bottom right. There is a small diagram showing open, slide to the right, and lock, slide to the left. Slide the little tray to the right until you hear a click. Lift up the silver tray, place the SIM card inside, following the diagram. The cut corner should be in the bottom left.

It does not really lock in place. It just sits there. Once it is positioned correctly, close the tray, press it down, and slide it to the left until it clicks.

Now replace the battery. Match the three contact points on the battery with the three metal contacts in the bottom right of the device and slide it in.

For the back cover, there is a plastic tab that lines up with a notch in the bottom left corner. If the cover is not oriented correctly, it will not go on, so make sure that lines up. Then snap it back into place all the way around.

We can now power on the device. Hold the power button until you see the welcome screen. If you do not see it, the battery is probably dead and you will need to charge it.

Installation Overview

For the next step, go to the Ray Hunter installation page. Open your browser and search for “EFF Ray Hunter GitHub.” It should be the first result. Make sure the URL is github.com/efforg/rayhunter.

Scroll down and click on “Installation Guide,” then select “Install from a release (recommended).” From here, the process becomes operating system specific. Use the timestamps in the video to jump to your OS, then come back to the final section afterward.

After Installation

Once installation is complete, you will notice a thin green line at the top of the device’s screen. That means Ray Hunter is running and nothing has been detected.

To access the web interface, connect your computer to the Wi Fi network broadcast by the device. Then open your browser and go to the IP address shown during installation, typically 192.168.1.180.

You should now see the Ray Hunter web interface.

Final Notes

Updating Ray Hunter is the same process as installation. Download the new version and run the installer again.

The interface is simple. You can see details about the current recording, view historical recordings, and review any alerts. There is also a test heuristic option you can enable to verify that detection is working. This mode is noisy, so remember to disable it afterward and reboot the device.

If you receive a legitimate alert, the FAQ in the installation guide explains where and how to submit that data if you want to help with further analysis.

If I get any alerts myself, I will make a follow up video analyzing the packet capture. While this device does not fix the problem, it does give us visibility. And honestly, it is just cool, which is more than enough reason to do something like this.

If you want, I can also:

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Break it into sections with anchors for a blog post

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Just tell me.

I don’t think you did the entire thing, you cut a bunch out

You’re right. I did cut a bunch out (mostly the OS-specific walkthrough parts and some repeated lines). Below is a full-length, cleaned transcript that keeps essentially everything, just with punctuation, capitalization, and obvious caption errors fixed. No em dashes. I also kept the structure readable for a website with headings.

Full Cleaned Transcript (Web-Ready)

Two weeks ago, Ben Jordan released a video covering a bunch of really cool tech, including the EFF’s Ray Hunter project. I’ll give a quick summary here, but I also wanted to make a step by step video showing how to install this on Windows, macOS, and Linux, mostly just to show how easy it is.

At the time of recording this, you can build one of these for between $25 and $40. But before we set anything up, let’s talk about why this thing exists.

Every phone has something called an IMSI, an International Mobile Subscriber Identity. It’s basically a unique ID tied to your cellular connection. Normally, when your phone connects to a network, that ID gets shared as part of the authentication process. That information is supposed to be gated behind warrants, probable cause, and the Fourth Amendment.

But that’s inconvenient if your job involves detaining people who haven’t actually committed crimes. So instead, the highest funded federal law enforcement agency in the United States, ICE, spends taxpayer money on fake cell towers. These devices, which are also known as IMSI catchers, impersonate legitimate cellular networks, and your phone automatically connects because that’s just how cellular standards work.

Once that happens, ICE isn’t just collecting identifiers and location data from their so called target. They’re collecting it from everyone nearby. And to make this kind of surveillance easier, these devices often force phones onto weaker, older protocols like 4G, 3G, or even 2G, where protections are worse or basically non existent.

So if you ever notice your phone suddenly dropping to an older network in a dense urban area where 5G is normally available, that can be a red flag.

If you or I tried this, we’d be committing multiple felonies. But when ICE does it, they call it enforcement. And because oversight is optional and accountability is rare, the burden ends up shifting to the public to notice when it’s happening.

And that’s where this device comes in.

Using cheap, discarded cellular hotspots and open source firmware from the EFF, we can turn throwaway hardware into portable IMSI catcher detectors. But before we begin, there is a legal disclaimer, so give that a read before you continue.

To be clear about what this actually is, this device is essentially doing a packet capture with a set of rules that look for specific patterns. Once one of those patterns is detected, it generates an alert and gets logged for later analysis.

I do want to be clear that just because an alert was generated does not mean an IMSI catcher was present. It just means something unusual happened, and it’s worth taking a closer look. And just because you don’t get any alerts does not mean everything is perfectly normal.

One more thing to note is that this device does need a SIM card inserted to work, but it does not have to be active. I’m using a $2 Mint Mobile SIM I picked up at Best Buy a couple years ago. You can also find them at places like CVS or Walgreens, but any SIM card should work.

Because this device uses a SIM, it does transmit an IMSI of its own, so it isn’t completely invisible. That IMSI could be logged by a carrier or by an IMSI catcher if you happen to encounter one.

This SIM isn’t meaningfully tied to you. There’s no active plan, no billing information, no name attached to it. Realistically, if you’re carrying this around, your phone is probably nearby or sitting right next to you. And that is by far the bigger privacy risk.

For this, I’ll be using the Verizon Orbit RC400L. If you don’t live in the United States, there are some other supported devices that will work in other countries.

If you aren’t here for the installation, you can skip to the last part of this video to see a demonstration of the interface. If you are here for the installation, the first couple steps are the same regardless of which OS you’re using. So let’s do that first.

Device Setup: Insert the SIM Card

So here’s my device. The first step is to insert the SIM card. One of the corners will have a notch taken out of it. You can either slip your fingernail in there, or if it’s the first time you’re taking the cover off, it is kind of difficult. So maybe use a butter knife or something else plastic you can pry it off with.

Once you get something in there, you basically just pull and it comes un-snapped.

On the back, we now see the battery. I miss the days of removable batteries. You can pry that up and take it out. I’m going to be blocking this out so you can’t see the details of my device.

Our SIM card goes in the bottom right. You’ll see a little diagram down here. It says open, slide to the right, lock, slide to the left. The little tray in the right hand corner, slide that to the right. You might hear a little click. You can then pick up the little silver part.

Grab your SIM card. Like I said, I’m just using a prepaid Mint Mobile SIM card that is not activated. Follow the little diagram. The cut off corner should be in the bottom left. Set that in the tray. It doesn’t really lock in. It kind of just sits there.

Once you have it in position, take the little silver thing, close it, press it down, and slide to the left. Again, you should hear a little click when it locks into place.

We can now replace our battery. Match up these three contact points with the three metal contact points in the bottom right. Slide in the battery.

For the back cover, you’ll notice this plastic tab on it that matches up to this notch in the bottom left hand corner. Place the cover on. If you don’t do it the right direction, the cover won’t go on. That’s why. Then just snap it back in place all around.

We can now power up our device for the next step. Hold the power button down until you see the welcome screen. If you don’t see that, your battery is likely dead, so go charge it for a few minutes.

Go to the Ray Hunter Installation Page

For the next step, we need to go to the Ray Hunter installation page. Regardless of which operating system you’re on, open your browser and type in: “EFF Ray Hunter GitHub.” It should be the first result.

“GitHub efforg/rayhunter, Rust tool to detect cell site simulators.” Click on that. Now double check the URL of the page you’re on to make sure you’re on the right page. It should be github.com/efforg/rayhunter.

Scroll down and click “Check out the installation guide.” Click “Installation Guide.” Once you’re on this page, we’re going to use “Install from a release (recommended).” Select that.

At this point, the video is going to be a choose your own adventure style. Either check the timestamps below, or go to the timestamps on the screen now, depending on the operating system you want to install from. Once you finish following your OS specific part, skip to the final section of the video and we’ll meet back up to discuss some final details.

macOS Installation

The first step is for TP-Link only. I’m not using TP-Link. I don’t know if you are, but I’m not. So we’ll go on to the second step.

Download the latest RayHunter.zip from the Ray Hunter releases page. Right below that, we’re on macOS. Depending on whether you’re on Intel, which is older MacBooks, or the new ARM-based ones like M1 or M2, you need to look for the correct name in the file.

In my case, I’m on an M processor, so I’ll be looking for “macOS ARM.” If you’re on Intel, look for “macOS Intel.”

Select the Ray Hunter releases page. The current version is 0.9.0. This might be different depending on when you’re watching this video. Scroll down to the Assets section. Click “Show all” assets, whatever number it is.

Here’s the ARM version. Here’s the Intel. Again, I’m on ARM, so I’m going to select this one. Make sure you’re selecting the one ending in .zip. The SHA-256 is just a file hash. You don’t want that. That’s not the actual files we need.

Select the .zip. Once that finishes, hit the back button in your browser.

Step three is to decompress the RayHunter.zip archive. Open Terminal and navigate to the folder. Be sure to replace x.x.x with the correct version number.

If you’ve never opened Terminal on your Mac, the easiest way is to open Finder, go to your Applications folder, scroll down to Utilities, and then toward the bottom you’ll see Terminal. Double click it. You can also use Spotlight. Press Command plus Spacebar, type Terminal, then press Enter.

Now that we have Terminal open, we need to cd, change directory, to our Downloads folder. That’s where Ray Hunter was downloaded.

Type: cd ~/Downloads

Then type: ls

You should see RayHunter.zip. You might have more files if you don’t clean out your Downloads folder.

The instructions show: unzip RayHunter.zip

Type unzip, then start typing RayHunter and hit Tab to autocomplete, then press Enter. You’ll see output.

Type ls again. You should now see the RayHunter folder.

You can type clear to make it easier to read.

Now change directory into the extracted folder: cd RayHunter

Type ls. If you see installer and other files, you’re in the right place.

Back on the instructions page, the next step is to connect to our device. If your device is already powered on, press the power button to see the output.

Press the Menu button on the top right. It’s a little hard to see on the camera. Cycle through the options. You’ll see 2.4 GHz Wi-Fi and 5 GHz Wi-Fi. I’m going to use 5 GHz Wi-Fi to connect. This is the Wi-Fi that the device is broadcasting for us to connect to.

Once you’re on 5 GHz, press the power button to select it. At the top you can see the name of the wireless network it’s broadcasting. In my case, Verizon RC400L-2. The password is on the bottom. I changed mine just for this video. You’ll likely see a random string of letters and numbers.

On your Mac, click the Wi-Fi icon, look for the network name, select it, and enter the password shown on the device. Once you connect, you’ll see a number one next to the Wi-Fi icon on the device, meaning one device is connected.

You can verify the connection by going back to your browser, opening a new tab, and going to 192.168.1.1 for Orbit. Type that in. It takes a minute to load.

If you’re correctly connected, you’ll see the Verizon Orbit page. We’re not going to log in here, but the default credentials are admin, and the password is your Wi-Fi password. If you want to log in later to check options or change anything, that’s where you can do it.

Now that we confirmed we’re connected, go back to the instructions.

On macOS only, you have to run a command to un-quarantine the installer. Copy that command, go back to Terminal, and paste it in. Right click and paste, then press Enter. There will be no output.

Now run the installer command for Orbit.

I’m only going to copy up to the first single quote because “my password” is just an example. Paste the command into Terminal. If you haven’t changed the admin password on your device, it defaults to the Wi-Fi network password.

Type the password, then close it with a single quote, and press Enter.

You’ll see output showing it sending the file to the device. Once it finishes, you should see: “Installation complete. Rebooting device.”

The device will reboot. The screen will go black. You should see the welcome logo again. Give it a minute to start up.

Once it starts up, you’ll notice a thin green line at the top. That means Ray Hunter is running and nothing is detected. That’s why it’s green.

To view the web interface, connect to the device’s Wi-Fi network again. If you forgot the network name, press the Menu button and cycle through until you get to Wi-Fi information.

Once connected, go to: 192.168.1.180

If you go there in your browser, you’ll see the Ray Hunter web interface.

That’s it for installation on macOS. You can now skip to the final part of the video.

Windows Installation

The first step is for TP-Link only. We’re not using TP-Link.

Second step: download the latest RayHunter.zip from the Ray Hunter releases page for your platform. For Windows, it’s Windows-x86_64.

Click the Ray Hunter releases page link. Current version is 0.9.0. Scroll down to Assets. Click “Show all” assets. Look for Windows x86_64. Make sure you’re downloading the one that ends in .zip. The SHA-256 file is not what we need.

Select the .zip file. Once it finishes, hit the back arrow.

Next, decompress the RayHunter.zip archive. On Windows, you can decompress using File Explorer.

Go to Downloads. You should see the RayHunter zipped file. Right click, choose “Extract All,” then click Extract. Once that finishes, it will open the extracted folder.

Select the folder. Hold Shift, then right click inside the folder. Choose “Open PowerShell window here.”

Now the next step is to connect to your device. If your device is powered on, tap the power button. Press the Menu button on the top right to cycle through options. Choose 5 GHz or 2.4 GHz Wi-Fi.

Press the power button to see details. It shows the Wi-Fi network name, for example Verizon RC400L-2, and the password. I set mine manually for this video. Yours is likely a random string.

On your computer, connect to that Wi-Fi network. Select it and connect. You’ll be prompted for the password. If you have connected before, it may be saved.

You might see a page pop up asking to activate the SIM. This is because the Mint SIM inside the device wants activation. We won’t be doing that.

Once connected, you can verify by visiting 192.168.1.1 in your browser. You should see the Verizon Orbit login page. We’re not going to log in, but the default credentials are admin and the Wi-Fi password shown on the device. This confirms you’re connected.

Close that tab.

Back to the instructions, the next step is to run the installer. Copy the command up to the first single quote. Paste it into PowerShell. Right click will paste.

Then type the password. By default, it’s the Wi-Fi password shown on the device. Close it with a single quote. Press Enter.

I got a weird error for some reason. I ran it again and everything worked.

You should see output like: sending file, device is rebooting. The device will reboot and show the welcome screen again. Give it a minute.

If everything worked, you’ll see a green line on the top of the device screen. That means Ray Hunter is running and nothing was detected.

Back on your computer, connect again to the Wi-Fi network broadcast by the device. Once connected, open a new tab and go to: 192.168.1.180

If everything was successful, you should see the Ray Hunter interface.

That’s it for installation on Windows. You can now skip to the final part of the video.

Linux Installation

For context, I’m performing this installation from a live boot of Ubuntu running off a USB stick.

The first step is for TP-Link only. I’m using the Verizon Orbit, so this is not applicable.

Second step: download the latest RayHunter.zip from the Ray Hunter releases page. On Linux, if you’re using x86_64, look for Linux-x86_64. If you’re on ARM, look for Linux-aarch64.

Select the Ray Hunter releases page. Current version is 0.9.0. It might be different depending on when you’re watching this. Scroll down to Assets. Click “Show all” assets.

In my case, I’m on x86_64, so I want Linux-x86_64. Make sure you select the one ending in .zip. The SHA-256 is the file hash. We want the .zip.

Download it, then hit the back button.

Next, decompress the RayHunter.zip archive. Open Terminal. How you open Terminal varies depending on your Linux setup. Usually you can search for Terminal and press Enter.

Change directory to Downloads: cd ~/Downloads

Type ls. Then unzip the file: unzip RayHunter.zip

Start typing RayHunter and hit Tab to autocomplete, then press Enter. Once it finishes, run ls. You’ll see the extracted folder.

Change directory into that folder: cd RayHunter

Type ls. If you see the installer in there, you’re in the right spot.

Next step is to connect to your device. Press the power button to turn on the screen if it’s off. Press the Menu button on the top right and cycle through the options.

I’m going to use 5 GHz Wi-Fi. Once you’re on that screen, press the power button. You’ll see the Wi-Fi name, for example Verizon RC400L-2, and the Wi-Fi password. I changed mine for this video. Yours will likely be random numbers and letters.

Connect your computer to the Wi-Fi network the device is broadcasting. Select it and type the password shown on the device.

You may get a prompt to sign into the network because the SIM is unactivated, but we don’t care.

You can confirm you’re on the right network by visiting: 192.168.1.1

If you’re in the right place, you’ll see the Verizon Orbit login page. We’re not logging in, but the default credentials are admin and the default Wi-Fi password shown on your device. You can log in later if you want to check options.

Close that tab and proceed.

Now run the installer. Copy the command up to the first single quote, because “my password” is just filler text. Paste it into Terminal. Then type the admin password, which by default is the Wi-Fi password shown on the device. Close with a single quote and press Enter.

You’ll see output: sending file, logged in, installation complete, rebooting device. The device will reboot.

You’ll see the welcome screen. Give it a minute to start up.

Back in Terminal, it will show the web interface address: 192.168.1.180

You can click it if it’s a link in your Terminal, or copy and paste it into your browser.

Once your device starts up, you’ll notice a green line at the top. That means Ray Hunter is running and has not detected anything.

Connect back to the hotspot Wi-Fi network. If you don’t see it right away, give the device more time. It can take a couple minutes for the Wi-Fi network to show up. Once connected, visit that IP address in your browser.

If everything worked, you should see the Ray Hunter web interface.

At this point, installation is complete on Linux. You can now skip to the final part of the video.

Final Section: Interface and Next Steps

So that was the installation process. Hopefully you were able to complete that successfully.

Updating is the same process as installation. Download the new version, run the installer command, and you’ll have the new version.

The interface is pretty simple. You get details on the current recording. There’s also a History section that shows past recordings and any that triggered alerts.

There’s also a way to test the heuristic detection if you have any doubt that it’s working. You can open the configuration, enable “test heuristic,” which is noisy, then select Apply and Restart. Give it a minute, then refresh your browser.

One note on that test configuration. You might need to reboot the device. Hold down the power button, turn it back on, and then you should start seeing the test warnings.

You can expand the entries and see the test analyzer output. Just remember afterward to disable that test mode, and to be safe, reboot the device again.

If you do receive a legitimate alert, their FAQ page in the installation guide has details on what and where to send that data if you want to help them out. They can look into it further.

If I get any alerts, I’ll make a video analyzing the PCAP. I’m not too familiar with this exact type of traffic, but I did spend years analyzing packets. Either way, it should be interesting to look at.

While this isn’t necessarily fixing any problems, it is giving us visibility. It’s also just cool, and that’s more than enough reason to do anything.