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    LAN to Non LAN Private Network

    Scheduled Pinned Locked Moved General pfSense Questions
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    • N Offline
      NOYB
      last edited by

      @Derelict:

      Packet capture on the inbound/LAN interface should yield a MAC address.

      Already know the local machines that are involved.  Have a LAN firewall log and pass rule for private networks that are not LAN network.  Then the float WAN out rule blocks.

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      • F Offline
        firewalluser
        last edited by

        UEFI bios? Bios virus have been around for a long time before UEFI and considering things like this, maybe flashing your bios on the machines in question might stop the behaviour?
        http://arstechnica.com/security/2013/10/meet-badbios-the-mysterious-mac-and-pc-malware-that-jumps-airgaps/

        I'm assuming you've ruled out dos root kits loading before windows?

        An interesting read which your economic well being amongst other things could depend on, if you want an idea of how innovative some of the thought processes can be. I'm sure some will see the links as nice propagation.
        NSA Journal of Information Warfare 2015
        https://cryptome.org/2015/08/nsa-jiw-2015.pdf
        NSA Journal of Information Warfare 2014
        https://cryptome.org/2015/08/nsa-jiw-2014.pdf

        Capitalism, currently The World's best Entertainment Control System and YOU cant buy it! But you can buy this, or some of this or some of these

        Asch Conformity, mainly the blind leading the blind.

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        • johnpozJ Offline
          johnpoz LAYER 8 Global Moderator
          last edited by

          seems odd that skype would send to those IPs..  Is that something that is resolving to those IPs.. I would flush the local cache on the machine, then doing a sniff on your pfsense with no limit on the packets (defaults to 100) and fire up your skype if you think that is what is kicking off the traffic - does it query for any names that resolve to those IPs for some strange reason?

          An intelligent man is sometimes forced to be drunk to spend time with his fools
          If you get confused: Listen to the Music Play
          Please don't Chat/PM me for help, unless mod related
          SG-4860 24.11 | Lab VMs 2.8, 24.11

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          • N Offline
            NOYB
            last edited by

            Just did some more Skype with friend.  And bang.  There it is.

            Did the net stat and Skype is using that port 38808 but to my friends WAN address.
            TCP    192.168.2.21:52077    50.43.x.x:38808    ESTABLISHED
            [Skype.exe]

            However there is a machine on my friends LAN with 192.168.1.8.

            Hmmm.  What is Skype trying to accomplish?

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            • F Offline
              firewalluser
              last edited by

              Hook this into skype http://www.rohitab.com/apimonitor and see what api's it's using.

              I wonder if advapi.dll is used or something else buried deep in the bowels of the OS which could suggest a new method of hiding functionality.

              Of course it could just be a bug which might turn out to be exploitable. Have you tried sending a simple text file between each other? I wonder if your machine HD FAT gets lifted as its quick and easy to lift that as its not particular big in relation to bigger files, omitting standard file locations of course from the FAT to further reduce what gets lifted.

              Capitalism, currently The World's best Entertainment Control System and YOU cant buy it! But you can buy this, or some of this or some of these

              Asch Conformity, mainly the blind leading the blind.

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              • johnpozJ Offline
                johnpoz LAYER 8 Global Moderator
                last edited by

                is the machine your friend on 192.168.1.8 or .6 for its private IP?  Or you saying its some other machine on his network and his machine is say 192.168.1.14

                An intelligent man is sometimes forced to be drunk to spend time with his fools
                If you get confused: Listen to the Music Play
                Please don't Chat/PM me for help, unless mod related
                SG-4860 24.11 | Lab VMs 2.8, 24.11

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                • N Offline
                  NOYB
                  last edited by

                  Yes friend could be using either of those.  The connection attempt seems to correspond to when I send a message rather than when receiving.

                  Firewall log timestamps correspond with Skype timestamps of my sent messages.

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                  • johnpozJ Offline
                    johnpoz LAYER 8 Global Moderator
                    last edited by

                    seems like a bug in skype that it would try sending to a rfc1918 address when its connected to other end via a public IP..  Be it you block it or not - it sure is not going to work ;)

                    An intelligent man is sometimes forced to be drunk to spend time with his fools
                    If you get confused: Listen to the Music Play
                    Please don't Chat/PM me for help, unless mod related
                    SG-4860 24.11 | Lab VMs 2.8, 24.11

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                    • F Offline
                      firewalluser
                      last edited by

                      @NOYB:

                      Yes friend could be using either of those.  The connection attempt seems to correspond to when I send a message rather than when receiving.

                      Firewall log timestamps correspond with Skype timestamps of my sent messages.

                      What happens when your friend changes their ip address, do you see a change in the ip address at your end?

                      And did you say it occurred after the skype call as well, or just during a skype call/chat?

                      Capitalism, currently The World's best Entertainment Control System and YOU cant buy it! But you can buy this, or some of this or some of these

                      Asch Conformity, mainly the blind leading the blind.

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                      • DerelictD Offline
                        Derelict LAYER 8 Netgate
                        last edited by

                        This sounds to me like Skype might be checking to see if the private addresses can communicate locally.

                        Chattanooga, Tennessee, USA
                        A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                        DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                        Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                        • N Offline
                          NOYB
                          last edited by

                          What is being seen currently is during a Skype session; when sending a message.

                          I with Derelict though.  Although that could potentially break if there was a local Skype client that happened to be listening on that same IP and port combination.  Very unlikely.  But still, seems to be of poor design.  Not good form in my opinion to do stuff like that and go around what the users have established.

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                          • DerelictD Offline
                            Derelict LAYER 8 Netgate
                            last edited by

                            I would think there is some crypto involved using keys that have been agreed upon over the Skype channels first, but with the Skype "malware" who knows.

                            Chattanooga, Tennessee, USA
                            A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                            DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                            Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                            • F Offline
                              firewalluser
                              last edited by

                              @Derelict:

                              This sounds to me like Skype might be checking to see if the private addresses can communicate locally.

                              Only one way to find out and thats to test the scenario, maybe even testing on different subnets behind the same gateway might be interesting.

                              Capitalism, currently The World's best Entertainment Control System and YOU cant buy it! But you can buy this, or some of this or some of these

                              Asch Conformity, mainly the blind leading the blind.

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