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    Urgent File Server behind Firewall got hacked

    Scheduled Pinned Locked Moved Firewalling
    26 Posts 9 Posters 4.2k Views
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    • johnpozJ Offline
      johnpoz LAYER 8 Global Moderator
      last edited by

      To be honest I know for sure that windows does not LOCK out the administrator account.  That would be really really bad idea.. Since anyone on the network could lock out the admin from admin the machines ;)

      Sure you can lock out account billy, but out of the box windows is not going to allow locking of the built in admin account.

      There is NEVER a reason that rdp should be exposed to the public internet - NEVER!!!  Now, if you need say some consultant to get into some server.  Sure in a pinch you could forward the traffic in.  But It should be done then when he is going to connect, and the forward should be locked down to the source IP he will be coming from.

      Even then - better choice would to let him vpn in, etc..  Or you could use some support software from your machine, and then let him in to your server via your rdp session. So you can watch what he is doing, etc.

      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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      • chpalmerC Offline
        chpalmer
        last edited by

        We don't use microsoft products for our email server.  (other than its a product running on Windows server machine.)

        We don't use webmail and setup usernames and (strong) passwords up for each of the desktops and in a case or two for their smartphones. Users never know their password for email.  We also use pfblocker to control whats coming from areas which we have no business or desire to hear from.

        The email server logs everything. We've never seen anyone actually try to hack into a username (other than "abuse") that we use here but you can't count on that. Its not if..  but when.

        But I think the point of this thread is-  We have enough with services that have to live with an open port or two in order to do their job. Don't open yourself up to more heartburn by opening up services to the world which can be easily set up on VPN's or other methods such as not allowing outside access at all. Or firewall rules allowing a set source.

        Triggering snowflakes one by one..
        Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

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        • A Offline
          ashima LAYER 8
          last edited by

          Hello,

          On the eve of new  year  my entire network seems to be hacked.

          To patch up things temporarily I placed new firewall ( just acting as load balancer and vpn server) before my previous firewall.

          So my current network is

          isp2 –----
                            |
                isp1----- load balancer ---- my old firewall ---- switches ----- Win Server, Desktops, APs.

          rdp and teamviewer are off WIn Server.....

          The LAN network of load balancer is 192.168.5.0/24 .  The WAN ip of old firewall is 192.168.5.2.

          Suddenly, the arp of load balancer shows 192.168.5.2 allotted to a new mac id de:ad:f9:xx:xx:xx. And the old firewall doesn't get the WAN IP and my entire LAN doesn't get internet access. This is happening every 20-25 min.  There are no vendor for mac id  de:ad:f9.

          I think some one internally intentionally  or unintensionally spoofing a mac id and taking up firewall wan ip.

          What should I do ? Meanwhile I have taken down my entire LAN network and connecting each device one by one to find the culprit. A tedious job but No other option.

          Please Help me and save my NEW Year.....

          Regards,
          Ashima

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          • H Offline
            Harvy66
            last edited by

            It's definitely intentional. The MAC address starts with the word "dead". You can't "accidentally" change you MAC address.

            Since you have no idea where this MAC address is coming from, your local network is physically unsecure. You should either use your switch to figure out which port the address is coming from or start disconnecting devices while attempting to ARP ping or something.

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            • johnpozJ Offline
              johnpoz LAYER 8 Global Moderator
              last edited by

              Its a locally admin mac, you can tell since de the 2nd significant bit is 1, so that is locally admin mac address.

              What is between your LB and your firewall?  I would take it just a wire and or a switch where you would of setup this 192.168.5 as a transit network - there should be no other devices on this network other than possible other routers..  You show –- so take it just a wire between your LB and your firewall?

              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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              • A Offline
                ashima LAYER 8
                last edited by

                @johnpoz there is just a wired connection between LB and the Firewall…..There is no other device between them.

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                • A Offline
                  ashima LAYER 8
                  last edited by

                  We literally removed almost all devices one by one almost 60 off them and reconnected them one by one. There are 3 more win 7 systems, win server, tally server and an AP which are yet be connected and tested. We shall continue the test tomorrow.

                  Meanwhile I have disabled DHCP in LB and given firewall a fixed ip.

                  What I don't understand how can a device connected to firewall LAN get a dhcp response from LB (dhcp was initially enabled in LB).

                  Any help please.

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                  • johnpozJ Offline
                    johnpoz LAYER 8 Global Moderator
                    last edited by

                    "There is no other device between them."

                    Then why are you bother to check all the other devices on your network???  mac address are layer 2.. They do not go beyond your layer 2 connection.  If all you have is a wire between your LB and Pfsense - then your issue is between those 2 devices - PERIOD!!!

                    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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                    • A Offline
                      ashima LAYER 8
                      last edited by

                      Hello,

                      A very Happy New Year to everyone.

                      Yes, There is just a wire between LB and firewall. That is what was surprising  me. The rogue mac id de:ad:b9:80:87:90 was in between getting the wan IP of the firewall, as a result there was no internet for the firewall clients.

                      I have disabled dhcp in LB and given firewall a static IP. This seems to have solved the issue.

                      I am also running Xarp ( a program to detect arp spoofing) in my lan. In between I get alerts

                      169.254.50.80      de:ad:b9:80:87:90

                      The same mac id but now it's not getting the ip address…. so the net is working fine. I guess someone has done mac spoofing and now running arp snoofing.....

                      Any clue ?

                      BTW I had enabled virtual Ip (IP alias) in my firewall if that has some thing to do with the case.

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                      • johnpozJ Offline
                        johnpoz LAYER 8 Global Moderator
                        last edited by

                        169.254 is link local address for ipv4..  Interface set for dhcp that does not get response from dhcp will assign itself a random address with 169.254 as well APIPA..

                        https://en.wikipedia.org/wiki/Link-local_address

                        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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                        • A Offline
                          ashima LAYER 8
                          last edited by

                          @johnpoz,    That is exactly what I want to tell 169.254 is link local address.

                          The rogue mac de:ad:b9  is unable to get a valid ip. But when I enable dhcp at the LAN port of LB, this rogue mac id  takes the WAN ip of firewall. At times more than one IP is assigned to same mac id. When I disable LAN and enable LAN back in LB, it disapears and firewall gets back its ip.

                          Any clue…..

                          Ashima

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                          • johnpozJ Offline
                            johnpoz LAYER 8 Global Moderator
                            last edited by

                            How is it a rouge mac, its a wire between your LB and pfsense - so clearly you set that mac up on pfsense.  Do an ifconfig and remove the mac..

                            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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