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    [SOLVED] Hacking on SSH even though no portforwarding or WAN rules that allow it

    Scheduled Pinned Locked Moved Firewalling
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    • DerelictD
      Derelict LAYER 8 Netgate
      last edited by

      And what port is sshd configured to listen on? (System > Advanced, Secure Shell, SSH Port)

      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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      • iorxI
        iorx
        last edited by

        I've changed port now for the ssh. It was present on default 22 before that.

        Going through the raw system.log to see if I can grasp what's going on here. Any particular info which should not be in the file if I'm to attach it here?

        It looks like the firewall lost power at 05:20 this morning. After that the attacks begun.

        Them' rules coming up, attached png.

        wan.png
        wan.png_thumb

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        • KOMK
          KOM
          last edited by

          Nothing there would allow ssh, if that's the complete list.  Anything in your floating rules?  What packages are you running, if any?

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          • iorxI
            iorx
            last edited by

            Floating rules only have an ICMP * * * * rule, right now.
            When pfBlockerNG is active there are some more.

            When I encountered the attack I changed the port of ssh and disabled pfblockerng, and started investigating. I'm going to restore that config and document how it looked here.

            This error in the system.log eludes me.
            Jan 26 05:25:28 fwna php-cgi: rc.bootup: New alert found: There were error(s) loading the rules: /tmp/rules.debug:29: cannot load "/var/db/aliastables/pfB_Firehol.txt": Invalid argument - The line in question reads [29]: table <pfb_firehol>persist file "/var/db/aliastables/pfB_Firehol.txt"

            Can that cause rules not to be loaded as they should?

            Attached are screen dumps.

            ![Screenshot-2018-1-26 Firewall Rules Floating.png](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall Rules Floating.png)
            ![Screenshot-2018-1-26 Firewall Rules Floating.png_thumb](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall Rules Floating.png_thumb)
            ![Screenshot-2018-1-26 Firewall pfBlockerNG Edit IPv4.png](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall pfBlockerNG Edit IPv4.png)
            ![Screenshot-2018-1-26 Firewall pfBlockerNG Edit IPv4.png_thumb](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall pfBlockerNG Edit IPv4.png_thumb)
            ![Screenshot-2018-1-26 Firewall Aliases Ports.png](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall Aliases Ports.png)
            ![Screenshot-2018-1-26 Firewall Aliases Ports.png_thumb](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall Aliases Ports.png_thumb)
            ![Screenshot-2018-1-26 Firewall NAT Port Forward.png](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall NAT Port Forward.png)
            ![Screenshot-2018-1-26 Firewall NAT Port Forward.png_thumb](/public/imported_attachments/1/Screenshot-2018-1-26 Firewall NAT Port Forward.png_thumb)</pfb_firehol>

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            • johnpozJ
              johnpoz LAYER 8 Global Moderator
              last edited by

              "It looks like the firewall lost power at 05:20 this morning. After that the attacks begun."

              If your rules do not load – then sure it could be like no firewall at all..

              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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              • KOMK
                KOM
                last edited by

                If your rules do not load – then sure it could be like no firewall at all..

                That makes sense, and yet it seems like incorrect behaviour for pf.  One glitch in the ruleset and it throws them all out and hangs your naked ass out on the Internet?  Wonderful.

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                • johnpozJ
                  johnpoz LAYER 8 Global Moderator
                  last edited by

                  Just saying it could happen… Yeah that is with any firewall.. If rules do not load should be block all, etc..  But all depends on the loading of the rules fail..

                  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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                  • DerelictD
                    Derelict LAYER 8 Netgate
                    last edited by

                    As far as I know it is only on reboot. If there is a problem loading the rule set after it is loaded the first time it simply does not apply the changed/bad rule set.

                    https://redmine.pfsense.org/issues/6028

                    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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                    • KOMK
                      KOM
                      last edited by

                      As far as I know it is only on reboot.

                      Good to know, thanks.

                      I suspect we can put this issue to bed.  A glitchy pfBlocker ruleset combined with a forced reboot equals pants totally down.

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                      • iorxI
                        iorx
                        last edited by

                        Yes, that explains the behavior before I disabled the pfblocker. I had no routing from within the LAN, could not ping anything outside the LAN.
                        Disabling pfBlocker triggered a reload of the rules, and with that it restored a working rule set.

                        I'm going for a rebuild and replace of this instance to be sure nothing was compromised. And is going to have a long hard look at the UPS procedure which should have taken this system down gracefully. Obviously they don't work as intended.

                        Although, the OpenVPN connecting this office to the HQ was working all along, even with the rule set not in place. Maybe not so strange as it operates directly on the WAN interface.

                        The scariest thing about this whole thing is that 05:25:24 the firewall came back from the unplanned power outage. 05:26:33 I see the first attempt for an unauthorized logon attempt, which then escalates into a flood of webadmin and ssh logins. Got a bunch of interesting login names tried anyway :-)
                        Src of attack: 5.101.40.10, 193.201.224.109, 103.79.143.141, 85.182.38.103
                        193.201.224.109 was some kind of robot, as it was checking for logon with the username in alphabetic order.

                        Thanks ladies and germs for helping me come to an explanation and closure!

                        Brgs,

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                        • johnpozJ
                          johnpoz LAYER 8 Global Moderator
                          last edited by

                          "05:26:33 I see the first attempt for an unauthorized logon attempt,"

                          Not really strange to see that… There is a shitton of noise on the net..

                          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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