{
  "description": "The search takes the DNS records and their answers results of the discovered_dns_records lookup and finds if any records have changed by searching DNS response from the Network_Resolution datamodel across the last day.",
  "asset_type": "Endpoint",
  "baselines": [
    {
      "id": "2296f721-8842-42ce-bfc7-74bd8c72b7c3",
      "name": "Discover DNS records",
      "product_type": "splunk"
    }
  ],
  "confidence": "medium",
  "creation_date": "2019-02-14",
  "data_metadata": {
    "data_models": [
      "Network_Resolution"
    ],
    "data_source": [
      "DNS"
    ],
    "providing_technologies": [
      "Splunk Stream",
      "Bro"
    ]
  },
  "detect": {
    "splunk": {
      "correlation_rule": {
        "notable": {
          "nes_fields": "src",
          "rule_description": "The table represents a list of DNS records and their responses for corporate domains that have recently changed",
          "rule_title": "DNS record changed"
        },
        "risk": {
          "risk_object": "src",
          "risk_object_type": [
            "system"
          ],
          "risk_score": 40
        },
        "scheduling": {
          "cron_schedule": "0 * * * *",
          "earliest_time": "-70m@m",
          "latest_time": "-10m@m"
        },
        "suppress": {
          "suppress_fields": "src",
          "suppress_period": "28800s"
        },
        "search": "| inputlookup discovered_dns_records.csv | rename answer as discovered_answer | join domain[|tstats summariesonly=true count values(DNS.record_type) as type, values(DNS.answer) as current_answer values(DNS.src) as src from datamodel=Network_Resolution where DNS.message_type=RESPONSE DNS.answer!=\"unknown\" DNS.answer!=\"\" by DNS.query | rename DNS.query as query | where query!=\"unknown\" | rex field=query \"(?<domain>\\w+\\.\\w+?)(?:$|/)\"] | makemv delim=\" \" answer |  makemv delim=\" \" type | sort -count | table count,src,domain,type,query,current_answer,discovered_answer | makemv current_answer  | mvexpand current_answer | makemv discovered_answer | eval n=mvfind(discovered_answer, current_answer) | where isnull(n)"
      }
    }
  },
  "entities":["dest"]
  "eli5": "Using a lookup `discover_dns_records` generated by support search \"Discover DNS records\" we check previous network traffic and make sure the responses have not changed.",
  "how_to_implement": "To successfully implement this search you will need to ensure that DNS data is populating the `Network_Resolution` data model. It also requires that the `discover_dns_record` lookup table be populated by the included support search \"Discover DNS record\". <br></br> <b>Splunk>Phantom Playbook Integration</b><br></br>If Splunk>Phantom is also configured in your environment, a Playbook called \"DNS Hijack Investigation\" can be configured to run when any results are found by this detection search. The playbook takes in the DNS record changed and uses Geoip, whois, Censys and PassiveTotal to detect if DNS issuers changed. To use this integration, install the Phantom App for Splunk <code>https://splunkbase.splunk.com/app/3411/</code>, add the correct hostname to the \"Phantom Instance\" field in the Adaptive Response Actions when configuring this detection search, and set the corresponding Playbook to active. <br/>(Playbook Link:<code>https://my.phantom.us/4.1/playbook/dns-hijack-investigation/</code>).<br></br>",
  "id": "44d3a43e-dcd5-49f7-8356-5209bb369065",
  "investigations": [
    {
      "id": "e211a8cf-35e7-4bb2-8140-e756cc06fd72",
      "name": "Get DNS Server History for a host",
      "product_type": "splunk"
    },
    {
      "id": "c096f721-8842-42ce-bfc7-74bd8c72b711",
      "name": "DNS record change investigation",
      "product_type": "phantom"
    }
  ],
  "known_false_positives": "Legitimate DNS changes can be detected in this search. Investigate, verify and update the list of provided current answers for the domains in question as appropriate.",
  "maintainers": [
    {
      "company": "Splunk",
      "email": "jhernandez@splunk.com",
      "name": "Jose Hernandez"
    }
  ],
  "mappings": {
    "cis20": [
      "CIS 1",
      "CIS 3",
      "CIS 8",
      "CIS 12"
    ],
    "kill_chain_phases": [
      "Command and Control"
    ],
    "mitre_attack": [
      "Exfiltration",
      "Command and Control",
      "Defense Evasion",
      "Commonly Used Port"
    ],
    "nist": [
      "ID.AM",
      "PR.DS",
      "PR.IP",
      "DE.AE",
      "DE.CM"
    ]
  },
  "modification_date": "2019-02-14",
  "name": "DNS record changed",
  "original_authors": [
    {
      "company": "Splunk",
      "email": "jhernandez@splunk.com",
      "name": "Jose Hernandez"
    }
  ],
  "responses": [],
  "security_domain": "network",
  "spec_version": 2,
  "product_type": "splunk",
  "version": "1.0"
}