How to tell if a device is using my network to gain personal or financial information.

HammertimeHammertime Member Posts: 3
edited November 7 in Devices & Security

How do I tell if someone is using my network in a way to gain personal or financial information?


I gave someone I’m just becoming friends with my WiFi password. They are currently on my network. I don’t know tech that well, open ports, pings, etc. id like to know if they are using access to my WiFi in an negative way

VioletChepilRobinCiaranNotta_Donkey1

Answers

  • MarcMarc Member Posts: 427 ✭✭✭✭✭
    edited November 7
    Hi @Hammertime, I’m guessing you might get a number of additional responses but if your that concerned, change you password and remove your friend from your network.  Otherwise you will find many routers support logging, that is the ability to see where traffic is going from the router to and from the internet. It’s usually turned off so you might need to turn it on. 
    Looking at the logs it could give you an idea of where your friend is going. There are also other products like wireshark that can be used to examine all traffic within your network. It’s a complicated product though so be aware. @kltaylor, @Pooh, @SimoneSpinozzi, @Pixelpopper...  any suggestions?
    Thats Daphnee, she's a good dog...
    VioletChepilNotta_Donkey1OKC
  • VioletChepilVioletChepil London, UKAdministrator Posts: 2,232 admin
    Thanks for your question. @Marc have added some great experts for feedback for advice. 
    Lets see what they can add to the thread. I'm just going to slightly modify the title of this post and promote it, to see if we can get some more answers as well. 

    Community Manager at Fing

    Hammertime
  • kltaylorkltaylor Member Posts: 558 ✭✭✭✭✭

    How do I tell if someone is using my network in a way to gain personal or financial information?


    I gave someone I’m just becoming friends with my WiFi password. They are currently on my network. I don’t know tech that well, open ports, pings, etc. id like to know if they are using access to my WiFi in an negative way

    This is why Guest Networks are the best solutions.

    You can use an application called Wireshark to determine traffic flow to an endpoint and what ports are being requested from the router/firewall.  However, @Marc is spot-on, change your password.  Please check to see if your brand of router allows for a guest wireless connection, and if so set that up and give your blossoming relationship partner that information.

    Honestly ask yourself 'Does this person and/or device need access to my LAN?'  If you answer 'No' to that, then do not provide access to them.

    Stay safe, and hope that your new friendship continues to grow.
    "There's a fine line between audacity and idiocy."
    -Warden Anastasia Luccio, Captain
    MarcVioletChepilOKC
  • VioletChepilVioletChepil London, UKAdministrator Posts: 2,232 admin
    I definitely agree with changing password. Do you know how to do this for your router @Hammertime ?
    What kind of router do you have?

    Community Manager at Fing

  • Notta_Donkey1Notta_Donkey1 Member Posts: 14 ✭✭
    Is there are reason you suspect this person? The reason why I ask is because I guess I am quite naive in this area, when I give my wifi number to a visitor I trust them and dont question their intentions. I would be interested to know if they done something or suggested something that made you suspicious in the first place?
    Question leading from this: if you change the password whilst somebody is already on the network, will they be automatically kicked out? or just blocked from accessing the next time they attempt to log in?
    vulcansheartVioletChepil
  • vulcansheartvulcansheart Member Posts: 18 ✭✭
    Is there are reason you suspect this person? The reason why I ask is because I guess I am quite naive in this area, when I give my wifi number to a visitor I trust them and dont question their intentions. I would be interested to know if they done something or suggested something that made you suspicious in the first place?
    Question leading from this: if you change the password whilst somebody is already on the network, will they be automatically kicked out? or just blocked from accessing the next time they attempt to log in?
    Changing the key will deauthenticate the other clients almost immediately.

    OP needs to change his password, enable the guest SSID and move the suspicious user over to it. If the guy asks what the deal is, just say it's got a better signal for him.
    41 4c 4c 20 59 4f 55 52 20 42 41 53 45 20 41 52 45 20 42 45 4c 4f 4e 47 20 54 4f 20 55 53
    Notta_Donkey1OKCVioletChepil
  • OKCOKC Member Posts: 8
    This may be a social experiment.  We aren't ready to give them a key to our house but what kind of person would we be for denying them Internet access? I mean its just internet right? The best answer -> guest wireless connection if possible.  Keep your checking account private though.
    vulcansheartGrammaKVioletChepilSeanie86
  • MarcMarc Member Posts: 427 ✭✭✭✭✭
    I’m with @OKC, guest network.  The problem with giving access to your core network’s WiFi is that its not just the internet that people have access to, its also all of your IoT devices exposed to whomever has access.  And even if they are not malicious, you never know what kind of malware or virus’s are installed on their devices that can affect a home.  The isolated guest network goes along way towards mitigating those issues.
    Thats Daphnee, she's a good dog...
    OKCvulcansheartGrammaKVioletChepil
  • CrowgrandfatherCrowgrandfather Member Posts: 34 ✭✭✭

    So a lot of people have recommended changing the WiFi password which I'll support; however I'll answer your other question directly.


    You can't easily. Wireshark was mentioned which is ok. Wireshark is a packet analyzer. If you don't know tech well it's not going to help you. There are entire certification courses for Wireshark it's that in depth. Wireshark also has another problem, it's not promiscuous. Wireshark can be promiscuous but that requires you to have a wireless NIC that supports promiscuous mode (which Windows doesn't allow). What this means is that Wireshark will only see traffic to and from the device that's running it. To see everything on your network you need either a Linux machine (in which case I'd recommend snort over Wireshark for this) or you need to enable a span port in your router.


    Furthermore you need to understand the nature of your network. Let's imagine your friend installed a proxy in your network to Man-In-The-Middle traffic. Your traffic to websites like banking, shopping, and most other things, is going to be TLS encrypted. With enough time and a NSA level super computer they could maybe crack the encryption and reply your network traffic, but I'd consider than unlikely. And then there's always a VPN as an added security measure. Of course then you're just trusting someone else.


    The short answer to the unasked question is that you shouldn't worry too much about that. Speaking from personal experience (legally) it's significantly harder to intercept credit card information then it seems. Speaking for my Law Enforcement experience you should be more concerned with them trying to access illegal content from your network.

    MarcvulcansheartVioletChepilHronos
Sign In or Register to comment.