t1071-004-dns

name	T1071.004_dns
description	Adversaries may communicate using the Domain Name System (DNS) application layer protocol to avoid detection/network filtering by blending in with existing traffic.
category	configuration
version	18.1
author	cyberstrike-official
tags	["mitre-attack","enterprise","t1071.004","command-and-control","linux","macos","windows","network-devices","esxi","sub-technique"]
technique_id	T1071.004
tactic	command-and-control
all_tactics	["command-and-control"]
platforms	["Linux","macOS","Windows","Network Devices","ESXi"]
mitre_url	https://attack.mitre.org/techniques/T1071/004
tech_stack	["linux","macos","windows","network devices","esxi"]
cwe_ids	["CWE-300"]
chains_with	["T1071","T1071.001","T1071.002","T1071.003","T1071.005"]
prerequisites	["T1071"]
severity_boost	{"T1071":"Chain with T1071 for deeper attack path","T1071.001":"Chain with T1071.001 for deeper attack path","T1071.002":"Chain with T1071.002 for deeper attack path"}

T1071.004 DNS

Sub-technique of: T1071

High-Level Description

Adversaries may communicate using the Domain Name System (DNS) application layer protocol to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

The DNS protocol serves an administrative function in computer networking and thus may be very common in environments. DNS traffic may also be allowed even before network authentication is completed. DNS packets contain many fields and headers in which data can be concealed. Often known as DNS tunneling, adversaries may abuse DNS to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.

DNS beaconing may be used to send commands to remote systems via DNS queries. A DNS beacon is created by tunneling DNS traffic (i.e. Protocol Tunneling). The commands may be embedded into different DNS records, for example, TXT or A records. DNS beacons may be difficult to detect because the beacons infrequently communicate with infected devices. Infrequent communication conceals the malicious DNS traffic with normal DNS traffic.

Kill Chain Phase

• Command and Control (TA0011)

Platforms: Linux, macOS, Windows, Network Devices, ESXi

What to Check

• Identify if DNS technique is applicable to target environment
• Check Linux systems for indicators of DNS
• Check macOS systems for indicators of DNS
• Check Windows systems for indicators of DNS
• Verify mitigations are bypassed or absent (2 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: DNS Large Query Volume

This test simulates an infected host sending a large volume of DNS queries to a command and control server. The intent of this test is to trigger threshold based detection on the number of DNS queries either from a single source system or to a single targe domain. A custom domain and sub-domain will need to be passed as input parameters for this test to work. Upon execution, DNS information about the domain will be displayed for each callout.