splunk_escuAnomaly

Large Volume of DNS ANY Queries

The following analytic identifies a large volume of DNS ANY queries, which may indicate a DNS amplification attack. It leverages the Network_Resolution data model to count DNS queries of type "ANY" directed to specific destinations. This activity is significant because DNS amplification attacks can overwhelm network resources, leading to Denial of Service (DoS) conditions. If confirmed malicious, this activity could disrupt services, degrade network performance, and potentially be part of a larger Distributed Denial of Service (DDoS) attack, impacting the availability of critical infrastructure.

Detection Query

| tstats `security_content_summariesonly` count FROM datamodel=Network_Resolution
  WHERE nodename=DNS "DNS.message_type"="QUERY" "DNS.record_type"="ANY"
  BY "DNS.dest"
| `drop_dm_object_name("DNS")`
| where count>200
| `large_volume_of_dns_any_queries_filter`

Author

Bhavin Patel, Splunk

Raw Content

name: Large Volume of DNS ANY Queries
id: 8fa891f7-a533-4b3c-af85-5aa2e7c1f1eb
version: 9
creation_date: '2020-04-29'
modification_date: '2026-05-13'
author: Bhavin Patel, Splunk
status: experimental
type: Anomaly
description: The following analytic identifies a large volume of DNS ANY queries, which may indicate a DNS amplification attack. It leverages the Network_Resolution data model to count DNS queries of type "ANY" directed to specific destinations. This activity is significant because DNS amplification attacks can overwhelm network resources, leading to Denial of Service (DoS) conditions. If confirmed malicious, this activity could disrupt services, degrade network performance, and potentially be part of a larger Distributed Denial of Service (DDoS) attack, impacting the availability of critical infrastructure.
data_source: []
search: |-
    | tstats `security_content_summariesonly` count FROM datamodel=Network_Resolution
      WHERE nodename=DNS "DNS.message_type"="QUERY" "DNS.record_type"="ANY"
      BY "DNS.dest"
    | `drop_dm_object_name("DNS")`
    | where count>200
    | `large_volume_of_dns_any_queries_filter`
how_to_implement: To successfully implement this search you must ensure that DNS data is populating the Network_Resolution data model.
known_false_positives: Legitimate ANY requests may trigger this search, however it is unusual to see a large volume of them under typical circumstances. You may modify the threshold in the search to better suit your environment.
references: []
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: Large Volume of DNS ANY Queries by $dest$
analytic_story:
    - DNS Amplification Attacks
asset_type: DNS Servers
mitre_attack_id:
    - T1498.002
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: network
security_domain: network