discover_dns_records.yml

name: Discover DNS records
id: c096f721-8842-42ce-bfc7-74bd8c72b7c3
version: 1
date: '2019-02-14'
author: Jose Hernandez, Splunk
type: Baseline
datamodel:
- Network_Resolution
description: The search takes corporate and common cloud provider domains configured
  under `cim_corporate_email_domains.csv`, `cim_corporate_web_domains.csv`, and `cloud_domains.csv`
  finds their responses across the last 30 days from data in the `Network_Resolution
  ` datamodel, then stores the output under the `discovered_dns_records.csv` lookup
search: '| inputlookup cim_corporate_email_domains.csv | inputlookup append=T cim_corporate_web_domains.csv
  | inputlookup append=T cim_cloud_domains.csv | eval domain = trim(replace(domain,
  "\*", "")) | join domain [|tstats `security_content_summariesonly` count values(DNS.record_type)
  as type, values(DNS.answer) as answer 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,domain,type,query,answer
  | outputlookup createinapp=true discovered_dns_records'
how_to_implement: To successfully implement this search, you must be ingesting DNS
  logs, and populating the Network_Resolution data model. Also make sure that the
  cim_corporate_web_domains and cim_corporate_email_domains lookups are populated
  with the domains owned by your corporation
known_false_positives: none
references: []
tags:
  analytic_story:
  - DNS Hijacking
  detections:
  - DNS record changed
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - DNS.record_type
  - DNS.answer
  - DNS.query
  security_domain: network