Windows 10: Microsoft assumes your consent in sharing your Wi-Fi, even if you don’t use Windows 10


Why not opt in?

Imagine this scenario.

A friend visits your house, and wishes to use your Wi-Fi.

You tell your friend your Wi-Fi password in confidence. They type it into their laptop, which has recently been upgraded to Windows 10.

Your friend’s laptop can now use your Wi-Fi connection, and you’re fine with that. After all, they’re your friend. You don’t believe they are going to abuse the privilege.

If you’ve chosen a complex, lengthy password like 7sAp{oMEmGD#YT)MzGdTLQM9C then chances are that your friend is not going to be able to remember your Wi-Fi password, even if they wanted to break your confidence.

So far, so good.

But there’s some bad news.

And that bad news is that your friend has Windows 10 installed on their laptop. And Windows 10 has a password-sharing feature called Wi-Fi Sense enabled by default.

Requiring just a click and the password being re-entered by your friend, Wi-Fi Sense allows your friend’s Skype and Outlook/Hotmail contacts (if they use Windows 10 or Windows 10 Mobile) to also log onto your Wi-Fi network, without you having to share your password with them. Access can also be shared with your friend’s Facebook friends if they choose to allow that.

In other words, complete strangers could now use your Wi-Fi without your permission.

Thanks for nothing Microsoft.

Oh, and your Wi-Fi password? That has been uploaded to a Microsoft server.

Extract from Microsoft FAQ on Wi-Fi Sense

Extract from Microsoft’s Windows 10 FAQ on Wi-Fi Sense

So, your friend’s friends and contacts can access your Wi-Fi, and the password is now stored on Microsoft’s server.

You never gave permission for the password to be shared with your friend’s contacts, or to be uploaded to Microsoft’s servers.

Inevitably, some people (me amongst them) aren’t happy about this.

Microsoft’s answer? If you don’t want Wi-Fi Sense to scoop up your password when you share it with a friend, and then share it with that friend’s friends and contacts you have to rename your Wi-Fi network.

Yes, that’s right. Even though you may not use Windows 10, and may not have ever spent a single buck on a Microsoft product, the onus is on you to change the SSID of your Wi-Fi network, by including by including _optout somewhere in the wireless network’s name.

So, if you don’t want the scenario I describe above to happen to you, you need to change the name of your Wi-Fi network and (of course) change the settings of any devices that you currently allow to legitimately connect to that wireless network, such as your Wi-Fi-enabled TV.

Never mind that many people won’t have the first clue about how to change the SSID settings of their Wi-Fi router.

Wi-Fi SenseIt seems to me that those owning Wi-Fi hotspots should have been required to “opt-in”, *not* opt-out, of having Microsoft mess around with who could access their wireless network.

You’d expect this kind of bad behaviour from Facebook or Google (in fact, Google already did it with its controversial StreetView Wi-Fi mapping a few years ago)- it’s disappointing to see Microsoft up to the same shoddy tricks.

In a nutshell, the onus should not be on Wi-Fi owners to change the names of their networks if they don’t want to be part of Microsoft’s Wi-Fi Sense shenanigans. Instead, the onus should be on Microsoft to convince us that there are good reasons why we might want to join in.

The reason why they’ve done it the way they have is because Microsoft knows that many people wouldn’t be keen on the idea.

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22 Responses

  1. Methods

    August 3, 2015 at 2:39 pm #

    A bit of FUD Mr. Cluley, I would recommend using something, actually putting eyes on it before writing. Usually helps to understand. First of all, the OPTION TO SHARE is enabled by default, it doesn’t auto share networks and only to and Skype contacts. If you want the option to share with Facebook, you have to deep dive into the settings and enable it. Then, in this scenario, your friend who has enabled sharing to Facebook gets a password from you and has to choose to share that network with their friends after they enter the credentials, that DOES NOT happen by default.

    If they did do all of that, assumingly by mistake (which is crazy), then one of their friends has to grab one of their Windows 10 devices and come to your house (assuming they know where you live) and yes then gain limited access to your network with no access to the devices on the network. And the password is not what’s being handed out, this is an encrypted paisley. Point is, none of that happens by default. Your friend has to choose to share your network.

    • Graham Cluley in reply to Methods.

      August 3, 2015 at 2:50 pm #

      Thanks Methods.

      I’ve updated my article to make clear that the sharing of Wi-Fi access with Facebook users requires an additional step, and that the password has to be re-entered to be shared. Thanks for that.

      But you’ve kind of missed the main point of my article - or maybe I didn’t express it clearly.

      I don’t run Windows 10. Why do I have to mess around with my Wi-Fi router settings in order to opt-out of this? Why didn’t Microsoft choose opt-in instead?

      I think we all know the answer to that. Because many owners of Wi-Fi routers simply wouldn’t opt in.

      • Methods in reply to Graham Cluley.

        August 3, 2015 at 3:12 pm #

        I get your point, I actually think Wi-Fi sense is irrelevant as a security risk and as a feature. On principle, you’re right. Practically though, nobody is going to come to your place with a Windows 10 device, accidentally or maliciously share access, and then one of their contacts finds your home and logs in with their Windows device.

        That is not risky IMO and also not useful, I think MS should scrap the entire feature to be honest with you and the way they have responded to the Insider Program would allow me to bet that there are some updates to the “feature” in the near future.

        I think its good people know about it, know to make sure their friends don’t accidentally share a network when you give out your PW but I don’t think Microsoft engineers and leadership sat down and said, “we shouldn’t make it an opt-in, nobody would use it, lets make it an opt-out” I think its more likely they created the feature first and then the opt-out as a way to patch the problem. That said, we don’t know and its not fair to publish the intent of a company without having any evidence to support your assertion.

        • Coyote in reply to Methods.

          August 3, 2015 at 6:22 pm #

          Practically though, nobody is going to come to your place with a Windows 10 device, accidentally or maliciously share access, and then one of their contacts finds your home and logs in with their Windows device.”

          That which you don’t expect is likely to happen at some point. And since you don’t expect it, it will bite you harder. Expect the worst. But it isn’t a matter of whether it WILL happen; it is a matter of CAN it happen.

          but I don’t think Microsoft engineers and leadership sat down and said, ‘we shouldn’t make it an opt-in, nobody would use it, lets make it an opt-out’ ”

          I don’t think he was stating it that way. While I could say how companies do tend to make it opt-out (because they want as many people to use it, as they can get to), I’ll go about it differently (besides, he has already pointed out some): you don’t think it is fair that he is publishing the intent of a company without having any evidence to support his assertion? I don’t think you have any evidence to say that his intent was to defame (or whatever you wish to call it) Microsoft, so much as raise awareness as to why this is a bad idea of Microsoft (and it is their idea; whether they did it without thinking - yes, yes, I know - or not is besides the point).

      • Mark in reply to Graham Cluley.

        August 4, 2015 at 10:26 am #

        I hope that we can opt out before connecting to our wifi network?


  2. Mike E Delta

    August 3, 2015 at 4:09 pm #

    I also have to re-iterate, there is an article by Ed Bott that clears up a lot of the misconception with this feature…yes the “Connect to networks shared by my contacts” options may be enabled by default but the actual networks themselves are 100% NOT shared until you specifically select and enable the sharing. So this is by no means whatsoever happening until you the user say so, even after that it really is very easy to disable and even make the network forgotten by each machine. The necessity to be actively on top of your security is still very real and everyone should always be looking out but this was never a case of invasion by Microsoft, as if this were the early 2000’s and they were lackadaisical about security. Also, despite whatever allegations anyone has made because of the Snowden thing a couple of years ago, Microsoft is seriously not so foolish as to be on the wrong side of the privacy argument. For whatever anyone says, they actually are more on our side and don’t need our stuff as much as Google does, but even Google isn’t that dumb. They will go toe-to-toe w/ the Fed because when it comes to business, they need their customers MORE than they need Johnny Law.

    • Coyote in reply to Mike E Delta.

      August 3, 2015 at 6:27 pm #

      For whatever anyone says, they actually are more on our side and don’t need our stuff as much as Google does, but even Google isn’t that dumb.”

      Yes they are. This has been shown time and again. The problem is they want it their way as much as possible and as often as possible. They prioritise themselves above others (on things besides profit/success of the company) so maybe they aren’t stupid so much as arrogant. But that isn’t all that appealing either.

  3. pissoff

    August 3, 2015 at 6:04 pm #

    will here is a brilliant idea from an average joe, go to your router and block all mac address except your family computer, if your friend wants to used the wifi then add their mac address to the router tada job done :D

    • Jon Fukumoto in reply to pissoff.

      August 4, 2015 at 12:43 am #

      Doing MAC filtering IS NOT meant to secure a wireless router because MAC addresses can be spoofed by using readily available software on the Internet which can temporarily change the MAC address on any network device. If you really want to keep people out, use WPA2 with a strong password and turn off WPS if your home router has it.

      • Adam in reply to Jon Fukumoto.

        August 4, 2015 at 2:23 pm #

        Just disable SSID broadcast, and vehemently deny you even have WiFi when your friends ask. Then look them dead in the face as you fire up Kodi and ask what they want to watch.

  4. i0n3l

    August 4, 2015 at 1:13 am #


    If you let the auth by WPA PSK and do a MAC check for only trusted computer yes BUT if you disable wpa and just check MAC adress, you are powned because i monitor your AP to see what MAC are trusted and associated whit your AccessPoint, i change my MAC for one of your AP trusted one and just have to click connect on your ssid, your AP thinks my computer is yours and im in.

    Dont rely on MAC adresses only.

  5. John Law

    August 4, 2015 at 1:43 am #

    I have got WIn10 installed - to see what privacy mess is being brought upon us. And quite frankly - it seems rather intrusive indeed. Been putting settings “off” for a full night, delving into the culprits of Win10.

    That is not to say - ALL is wrong here. BUT beware: this Win10 upgrade seems much more to be about mass-data-acquiring-on-users , comparable and perhaps even beyond Google. IT IS ALL ABOUT THE MONEY, GUYS ! Just take a look at the feel-good-advertising-opt-in-video put up by MS and it makes you puke (if not just for the music in the background :o)

    @Mike E Delta:
    “Also, despite whatever allegations anyone has made because of the Snowden thing a couple of years ago, Microsoft is seriously not so foolish as to be on the wrong side of the privacy argument. For whatever anyone says, they actually are more on our side and don’t need our stuff as much as Google does, but even Google isn’t that dumb. They will go toe-to-toe w/ the Fed because when it comes to business, they need their customers MORE than they need Johnny Law.”

    NO WAY - this is simply about big bucks - meanwhile leaving Win users with a devastation on privacy.

    In all: the Wifi-Sense stuff is INTRUSIVE indeed to anyone. I don’t freakin’ care whether I’d be a Win10 , Win 8 or Linux Ubuntu user. I just do not want my systems to be intruded without my consent. PERIOD! .

    I am no conspiracy kind of person - but ehmmm… the net is slowly but consistently closing on all of us, people… Now guess who has access (OH YEAH - DON’T BE FOOLED!!!) to these oh-so-securely-encrypted Wifi-Sense passwords? Yes, that is a nice quizz…

    Let me tell you: there are three letters to it - and I’ll give you two of those:
    ??? .….

    The net is closing.
    We’re on the brink of all becoming lemmings.

    Sorry to see.

  6. gadget37

    August 4, 2015 at 10:21 am #

    What no-one seems to have mentioned is that most home wifi networks are open, this means not only do friends-of-friends-of-friends on Skype now have access to your bandwidth, they also have access to all your computers, servers, routers etc. on your internal network. Really insecure! You are right that Microsoft should disable this. If you give out your router password, the circle knowing that should be restricted to those you know personally. I guess we are now going to have to change WiFi passwords on a monthly basis as well… sigh…

    • Graham Cluley in reply to gadget37.

      August 4, 2015 at 10:24 am #

      From Microsoft’s Wi-Fi Sense FAQ:

      When you share network access, your contacts get Internet access only. For example, if you share your home Wi‑Fi network, your contacts won’t have access to other computers, devices, or files stored on your home network. If you have a small business that has intranet sites, your contacts won’t be able to access them.”

      Furthermore, from the sound of things the sharing should not extend to friends-of-friends-of-friends. If Bill gains access to Steve’s Wi-Fi through Wi-Fi Sense, then Bill shouldn’t be able to pass on access to his friend Satya.

      Of course, if Steve simply *tells* Bill his Wi-Fi password (as in my example in the article), then Bill’s Windows 10 PC will share it with Satya.

      • Adam in reply to Graham Cluley.

        August 4, 2015 at 2:28 pm #

        I’d like to see how MS manages to only grant Internet access. Do they create a virtual switch on the Win10 box and put all of their contacts on a VLAN? Because if they just “hide” the machines, that’s not going to keep anyone with even an ounce of curiosity and technical experience from enumerating the entire network.

  7. Alfons

    August 4, 2015 at 12:37 pm #

    Knowing that all wifi password will be stored in Microsoft Server, then it is another risk factor. Perhaps somebody can make use of Wifi passwords profile out of it :).

  8. David

    August 4, 2015 at 2:13 pm #

    So why do *I* need to change my SSID to _optout? Why can’t I make it _optin if I want to participate?

    Am I going to have to change my email address to

    What else am I going to have to add _optout to?

  9. Me

    August 4, 2015 at 7:28 pm #

    Or just don’t let friends attach to your network if they have a Windows machine. Tell them to pair with their cellphone if they need to access email.

    This might sound rude, but rude seems to be necessary to preserve privacy these days. I blocked incoming Gmail a few years back when I learned that Google captures contacts and text from people who respond to emails sent by people with Gmail accounts. In other words, Google uses your emails to Gmail users to build a profile on you regardless of whether you use their products or not (I don’t … DuckDuckGo & my own domain & Vimeo instead of Youtube & definitely no G+).

    I told all my friends that if they wanted to email with me, they had to do it with non Gmail accounts. Period. No exceptions. (acutally and non-Yahoo email accounts too - same reason)

    There are a few people I no longer trade emails with. Trust me, it’s no big loss. If they want to go have a beer with me, they pick up the phone. It has had zero impact on my professional and social life. That’s what I think most people miss… this constant-connection BS is just that. BS. You don’t need Google or Yahoo or Microsoft or Apple or any other tech company. They are all 100% and very easily expendable. If they misbehave, you can slice them off and throw them away more easily than you would think. Try it some time. You might be surprised.

  10. Brian Milnes

    August 5, 2015 at 8:45 am #

    Hi Graham,
    Can you check out this statement, made elsewhere?
    (after striking out “shared by default”) “My bad - Win10 shares your saved Wi-Fi passwords with other devices signed into your Microsoft account by default, but not through Wi-Fi Sense”
    Clarification would be good…

    • Graham Cluley in reply to Brian Milnes.

      August 5, 2015 at 9:01 am #

      Hi Brian

      Yes, I believe that Windows 10 will synchronise your Wi-Fi passwords via OneDrive (if you’ve signed into a Microsoft account) with other devices signed into that same account. In other words, if you have a Microsoft Surface or Windows Phone and enter a Wi-Fi password to connect to a hotspot, those credentials will also be shared with your Windows 10 laptop.

      I believe this feature was introduced in Windows 8, and it sounds like different functionality than Wi-Fi Sense.

      Hope that helps

      • John in reply to Graham Cluley.

        August 5, 2015 at 9:23 am #

        Gosh… I had not realized that before. In essence, that is bad too: wifi keys sitting on someone else’s (MS, which means NSA/GHCQ) servers … Darn…

        (“It is sooooo convenient” MS would argue , yeah sure - as if anyone would be too stupid to punch in a [strong] wifi password on the first time connection of a new device to a router. How many people would be doing so on a daily basis? Pratically no one.)

        Do you know of any opt-out for this? Some backgroud/references much appreciated - in order to kill this function, while remaining on an MS online account? THANKS!

        You see - I tend to think I need that MS online account still, in order to get to a couple of my bought apps onto my machines (Correct me if I’ m wrong though, and I’ll kill the whole MS-online connection straight away after all).

  11. Robert Kok

    August 10, 2015 at 12:57 pm #

    Brilliant. Google already requires _nomap at the end of a SSID to opt out from their location services and now Microsoft requires _optout. So my SSID will look like _optout_nomap and guest_optout_nomap for my guest network.

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