name: DNS Amplification Attacks
id: e8afd39e-3294-11e6-b39d-a45e60c6700
version: 1
date: '2016-09-13'
author: Bhavin Patel, Splunk
type: batch
description: DNS poses a serious threat as a Denial of Service (DOS) amplifier, if
  it responds to `ANY` queries. This Analytic Story can help you detect attackers
  who may be abusing your company's DNS infrastructure to launch amplification attacks,
  causing Denial of Service to other victims.
narrative: 'The Domain Name System (DNS) is the protocol used to map domain names
  to IP addresses. It has been proven to work very well for its intended function.
  However if DNS is misconfigured, servers can be abused by attackers to levy amplification
  or redirection attacks against victims. Because DNS responses to `ANY` queries are
  so much larger than the queries themselves--and can be made with a UDP packet, which
  does not require a handshake--attackers can spoof the source address of the packet
  and cause much more data to be sent to the victim than if they sent the traffic
  themselves. The `ANY` requests are will be larger than normal DNS server requests,
  due to the fact that the server provides significant details, such as MX records
  and associated IP addresses. A large volume of this traffic can result in a DOS
  on the victim''s machine. This misconfiguration leads to two possible victims, the
  first being the DNS servers participating in an attack and the other being the hosts
  that are the targets of the DOS attack.\

  The search in this story can help you to detect if attackers are abusing your company''s
  DNS infrastructure to launch DNS amplification attacks causing Denial of Service
  to other victims.'
references:
- https://www.us-cert.gov/ncas/alerts/TA13-088A
- https://www.imperva.com/learn/application-security/dns-amplification/
tags:
  analytic_story: DNS Amplification Attacks
  category:
  - Abuse
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  usecase: Security Monitoring
