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    snort (SID 43687) blocks root DNS servers ?!

    Scheduled Pinned Locked Moved IDS/IPS
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    • chudakC
      chudak @NogBadTheBad
      last edited by

      @nogbadthebad
      OK

      I don't see anything yet on LAN, all only on WAN.

      Let's wait :)

      NogBadTheBadN 1 Reply Last reply Reply Quote 0
      • NogBadTheBadN
        NogBadTheBad @chudak
        last edited by

        @chudak said in snort (SID 43687) blocks root DNS servers ?!:

        @nogbadthebad
        OK

        I don't see anything yet on LAN, all only on WAN.

        Let's wait :)

        0_1530654459156_Untitled.jpeg

        Andy

        1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

        chudakC 1 Reply Last reply Reply Quote 0
        • chudakC
          chudak @NogBadTheBad
          last edited by

          @nogbadthebad

          0_1530654781856_snort2.png

          1 Reply Last reply Reply Quote 0
          • NogBadTheBadN
            NogBadTheBad
            last edited by NogBadTheBad

            f.root-servers.net = 192.5.5.241 guessing thats from your WAN interface.

            Or your hosts directly query f.root-servers.net

            Andy

            1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

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            • NogBadTheBadN
              NogBadTheBad
              last edited by NogBadTheBad

              @chudak said in snort (SID 43687) blocks root DNS servers ?!:

              43687

              Err that rule by default is default disabled:-

              0_1530655816916_Untitled.jpeg

              0_1530655711176_Untitled.jpeg

              Maybe your being a bit over zealous with enabling the rules :)

              The two rules do differ slightly as well:-

              INDICATOR-COMPROMISE:-
              
              alert udp $HOME_NET any -> any 53 (msg:"INDICATOR-COMPROMISE Suspicious .top dns query"; flow:to_server; byte_test:1,!&,0xF8,2; content:"|03|top|00|"; fast_pattern:only; metadata:policy max-detect-ips drop, policy security-ips drop, service dns; reference:url,en.wikipedia.org/wiki/.top; classtype:misc-activity; sid:43687; rev:2;)
              
              Emerging DNS:-
              
              alert udp $HOME_NET any -> any 53 (msg:"ET DNS Query to a *.top domain - Likely Hostile"; content:"|01 00 00 01 00 00 00 00 00 00|"; depth:10; offset:2; content:"|03|top|00|"; fast_pattern; nocase; distance:0; threshold:type limit, track by_src, count 1, seconds 30; reference:url,www.symantec.com/connect/blogs/shady-tld-research-gdn-and-our-2016-wrap; reference:url,www.spamhaus.org/statistics/tlds/; classtype:bad-unknown; sid:2023883; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, deployment Perimeter, signature_severity Major, created_at 2017_02_07, updated_at 2017_02_07;)
              

              Andy

              1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

              chudakC 1 Reply Last reply Reply Quote 0
              • chudakC
                chudak @NogBadTheBad
                last edited by

                @nogbadthebad
                that could be and is an answer to the initial question, alto I don't recall changing rules until recently I saw my network being blocked

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                • NogBadTheBadN
                  NogBadTheBad
                  last edited by

                  .tk domains too :)

                  0_1530657362638_Untitled.jpeg

                  Andy

                  1 x Netgate SG-4860 - 3 x Linksys LGS308P - 1 x Aruba InstantOn AP22

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                  • BBcan177B
                    BBcan177 Moderator
                    last edited by

                    You can add "top" and "tk" to the DNSBL TLD Blacklist which will prevent these alerts since the DNS request will never be answered for those TLD Domains.

                    "Experience is something you don't get until just after you need it."

                    Website: http://pfBlockerNG.com
                    Twitter: @BBcan177  #pfBlockerNG
                    Reddit: https://www.reddit.com/r/pfBlockerNG/new/

                    chudakC 1 Reply Last reply Reply Quote 0
                    • chudakC
                      chudak
                      last edited by

                      That’s interesting, added, thx

                      1 Reply Last reply Reply Quote 0
                      • chudakC
                        chudak @BBcan177
                        last edited by

                        @bbcan177 would it make sense to black list all top domains listed here https://www.spamhaus.org/statistics/tlds/ ?

                        BBcan177B 1 Reply Last reply Reply Quote 0
                        • BBcan177B
                          BBcan177 Moderator @chudak
                          last edited by

                          @chudak said in snort (SID 43687) blocks root DNS servers ?!:

                          @bbcan177 would it make sense to black list all top domains listed here https://www.spamhaus.org/statistics/tlds/ ?

                          Its not a one-size-fits-all... Most of those TLDs most users will never need to access, so I would see little issue. There is also the TLD Whitelist, where you can allow some specific domains thru that are being blocked via TLD Blacklist.

                          There is also this TLD list: http://toolbar.netcraft.com/stats/tlds

                          "Experience is something you don't get until just after you need it."

                          Website: http://pfBlockerNG.com
                          Twitter: @BBcan177  #pfBlockerNG
                          Reddit: https://www.reddit.com/r/pfBlockerNG/new/

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