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How to block this type attack?

Scheduled Pinned Locked Moved Firewalling
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  • ?
    Guest
    last edited by Feb 3, 2015, 12:14 AM

    My LAN Server send many outgoing TCP packets  and states exhaust

    I use tcpdump

    20:53:49.280616 IP a.b.c.d.34574 > 122.226.161.51.7000: Flags S, seq 1758704997, win 61437, length 0
    20:53:49.280635 IP a.b.c.d.49465 > 122.226.161.52.7000: Flags S, seq 1985270926, win 64414, length 0
    20:53:49.280657 IP a.b.c.d.31893 > 122.226.161.53.7000: Flags S, seq 1917753334, win 63902, length 0
    20:53:49.280677 IP a.b.c.d.34245 > 122.226.161.54.7000: Flags S, seq 1672920662, win 63726, length 0
    20:53:49.280698 IP a.b.c.d.43872 > 122.226.161.55.7000: Flags S, seq 1962787171, win 64507, length 0
    20:53:49.280716 IP a.b.c.d.54136 > 122.226.161.56.7000: Flags S, seq 932930625, win 60665, length 0
    20:53:49.280734 IP a.b.c.d.2144 > 122.226.161.57.7000: Flags S, seq 1030524293, win 61229, length 0
    20:53:49.280753 IP a.b.c.d.50707 > 122.226.161.193.7000: Flags S, seq 346594498, win 60130, length 0
    20:53:49.280771 IP a.b.c.d.29773 > 122.226.161.194.7000: Flags S, seq 612510536, win 61080, length 0
    20:53:49.280789 IP a.b.c.d.35494 > 122.226.161.195.7000: Flags S, seq 877077015, win 63727, length 0
    

    Then I add tcp rules and use "Maximum new connections / per second(s) (TCP only)" option (10/1)

    But virusprot table is empty

    Anyone know how to get it working?

    Thanks

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    • D
      Derelict LAYER 8 Netgate
      last edited by Feb 3, 2015, 12:26 AM

      Why is your LAN server port scanning?

      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)

      1 Reply Last reply Reply Quote 0
      • ?
        Guest
        last edited by Feb 3, 2015, 12:46 AM

        To put it precisely,ths server is hacked and it attack others

        But I don't know why it not working when I use the virusprot settings

        1 Reply Last reply Reply Quote 0
        • D
          Derelict LAYER 8 Netgate
          last edited by Feb 3, 2015, 12:49 AM

          So fix the damn server.

          At least put a block rule on LAN that blocks from that server port any to any port tcp/7000 until you figure it out.

          Don't hassle with some package that obviously doesn't work very well.  Shut that nonsense down.

          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)

          1 Reply Last reply Reply Quote 0
          • C
            cmb
            last edited by Feb 3, 2015, 1:20 AM

            @Derelict:

            So fix the damn server.

            At least put a block rule on LAN that blocks from that server port any to any port tcp/7000 until you figure it out.

            Don't hassle with some package that obviously doesn't work very well.  Shut that nonsense down.

            This. Though take it a step further, block everything sourced from that server until you figure it out and get it cleaned. Ideally take the infected server off the network entirely, you don't want a compromised server online.

            1 Reply Last reply Reply Quote 0
            • J
              johnpoz LAYER 8 Global Moderator
              last edited by Feb 3, 2015, 11:43 AM

              Unplug the damn thing!!  WTF people???

              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 2.7.2, 24.11

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              • ?
                Guest
                last edited by Feb 3, 2015, 3:09 PM

                Sorry, My English is bad….

                I think everyone misunderstand this thing

                When attack occurs,states exhaustion, i unplug WAN port,and test Internal

                I hope attack can be blocked by pfsense first time,and prevent states exhaust next time

                SO Simply I wanna to know how to avoid hacked server(not managed by me) exhaust states

                Instead of use pfsense firewall(i manage it)and  hacked server is still online

                Express bad was my fault....

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                • L
                  lowprofile
                  last edited by Feb 3, 2015, 3:18 PM

                  Yeah….

                  Anything can happen when they are inside your network. How much memory do you have?

                  1 Reply Last reply Reply Quote 0
                  • H
                    Harvy66
                    last edited by Feb 3, 2015, 3:22 PM

                    He wants to know how to reduce the chance of a single hacked box from inadvertently taking down the entire network from state exhaustion.

                    PFSense does have an option in the top left web admin menu that allows for a reduction of state lifetime as states fill up. Simply put, the more states you have, the shorter they live without being kept alive. Since the issue is SYN packets creating states, but no real traffic after the fact, you don't want these states lasting the default 24 hours. As states fill up, the idle life will approach 0 seconds, allowing these unused states do quickly die off.

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                    • D
                      Derelict LAYER 8 Netgate
                      last edited by Feb 3, 2015, 4:27 PM

                      @johnpoz:

                      Unplug the damn thing!!  WTF people???

                      My concern is not with OP, but with everyone else.  He obviously doesn't care he has an infected computer on his network and wants to do research with it.

                      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)

                      1 Reply Last reply Reply Quote 0
                      • K
                        kejianshi
                        last edited by Feb 3, 2015, 4:40 PM

                        If you have a hacked box in your network, do not try to clean it or fix it.

                        Wipe it.  Reinstall from fresh.  (Not from a pirated ISO that contains lord know what)

                        Reconfigure.

                        Done.

                        In my opinion, there is no such thing as good virus protection.  Some just suck slightly less than others.

                        If you have an OS that needs virus protection, no matter what virus protection you buy, its only a matter of time till its infected.

                        Get used to wiping and reinstalling if you use windows in a way that exposes it to risks.

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                        • D
                          doktornotor Banned
                          last edited by Feb 3, 2015, 5:12 PM

                          Help: I Got Hacked. Now What Do I Do?

                          The only way to clean a compromised system is to flatten and rebuild. That’s right. If you have a system that has been completely compromised, the only thing you can do is to flatten the system (reformat the system disk) and rebuild it from scratch (reinstall Windows and your applications). Alternatively, you could of course work on your resume instead, but I don’t want to see you doing that.

                          P.S. Let me repeat: Unplug the infected shit from Internet!!!

                          1 Reply Last reply Reply Quote 0
                          • K
                            kejianshi
                            last edited by Feb 3, 2015, 5:21 PM

                            BTW - I would guess whoever is in your network is scanning for new things to infect, CC or private info to steal…

                            All I know for sure is it isn't good so unless you are a forensics expert working for law enforcement, can't imagine why you would just let the hack keep running.

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