Windows & Hunt for the Hidden Wi-Fi Network

Updated: June 17, 2024

This could be a good name for a new Clancy's blockbuster. Or something. Now listen. A friend of mine contacted me (yes I do have friends), and told me how his Windows laptop shows a Hidden network in the list of Wireless networks that he can use. He had no idea whence it comes. I said, interesting, would you like me to help. And so I began a lil' sleuthing operation. The plot thickens.

I brought my own hardware to test, as I assume other people's devices aren't necessarily configured correctly, and so, I don't want to use bad data to make wrong assumptions - I want to use good data to make wrong assumptions. I fired up my Linux laptop, and I couldn't see any hidden networks using some basic tools in a terminal. I then booted a Windows laptop, and lo and behold, the hidden access point was there. I started moving around his house, and the signal strength wouldn't drop. I assumed this may be a Windows bug. Or is it?

Investigatorizing

My friend does have a somewhat "smart" home. This means light bulbs that can change their hue, and they use a remote for that. I think there's also an app, but he hasn't configured it. However, the lights probably have their own antennas, and they are most likely active (all the time). Furthermore, the friend uses a mesh setup for his Wireless connectivity, with one main router and two extenders.

I assumed that perhaps the hidden network functionality could be related to the mesh, but I needed to verify that. This was also a great opportunity to see if some of the other devices in his home might actually be equipped with an antenna, even without being used. Things like printers, TVs, and fridges come to mind.

Enter NirSoft WifiInfoView

If you're not familiar with NirSoft, we're talking about an amazing bundle of utilities for everything Windows. Since forever, NirSoft (and Sysinternals) tools have always been part of my Windows toolbox. I have also included NirSoft on my list of greatest sites. In general, whenever I have a problem with one of my Windows boxes, I check if there's a NirSoft tool that can handle it. When it comes to Wi-Fi, sure, of course there is, and it's called WifiInfoView. Let's start and run, see what gives.

As soon as I ran it, the tool showed a whole lot of SSIDs, including all of my friend's, some neighbors', and then, lo and behold, a total of eight Hidden networks! So It wasn't a Windows bug. Each of these networks had a proper Mac address, type, channel, bandwidth, all the bits and pieces. But no company name or router model. The utility could not recognize these right away.

Hidden networks, list

Digging in deeper

I found the output fascinating. And I noticed a number of interesting details:

So far, the information strongly indicated the hidden networks were part of the mesh system anyway, perhaps even the exact same network adapters in some of the cases, but not all of them. I wanted to see if there was any other bit of data that would unequivocally prove that.

I then noticed that the Start time for the hidden networks was identical to the Start time for the router and the two extenders. They didn't all match exactly to one particular timestamp (I guess one of the extenders was rebooted, or brought online separately from the rest, and such), but overall, they all did match in some way. Two of the hidden networks matched one of the extenders, two or three matched another, etc.

Hidden networks, start time

And so, I told my friend he can doff his tinfoil hat and go back to having fun.

Conclusion

If you use a Windows machine, and you see a Hidden network shown in the list - when you don't expect it, that is, right - this is (most likely) fine. There can be many networks that do not broadcast their SSID. But if you see one in your own home, and you live in a less cluttered environment where you wouldn't necessarily expect to see any, you may wonder what gives. To figure it out exactly, you can use the WifiInfoView utility to display all of the networks within range, and use various pieces of information to map the adapters, antennas and routers around you. This could be quite revealing. Literally. Hi hi.

I found this exercise quite fascinating. I also learned more about my friend's house's topology. No, his lights don't have antennas, it seems. His fridge and TV also have no built-in router capabilities. His TV definitely has a Wireless network adapter, but it does not act as an access point. We also learned the reason why the signal strength for the hidden networks did not drop when moving about his place is because he had extenders positioned here and there so they offer optimal coverage, duh. In all of the cases, the hidden networks were simply part of the mesh system backbone, which allows the devices to communicate among them, without piggybacking on the user-defined networks, and thus degrading the service quality. Well, I hope this was mildly fun and educative. If you encounter a similar issue, and you can't put it to rest, fire up WifiInfoView and see what gives. See you around.

Cheers.