Official Description

Adversaries may perform calculations on addresses returned in DNS results to determine which port and IP address to use for command and control, rather than relying on a predetermined port number or the actual returned IP address. A IP and/or port number calculation can be used to bypass egress filtering on a C2 channel.(Citation: Meyers Numbered Panda)

One implementation of [DNS Calculation](https://attack.mitre.org/techniques/T1568/003) is to take the first three octets of an IP address in a DNS response and use those values to calculate the port for command and control traffic.(Citation: Meyers Numbered Panda)(Citation: Moran 2014)(Citation: Rapid7G20Espionage)
Tactics
Command And Control
Platforms
ESXi, Linux, macOS, Windows
Parent Technique
T1568 · Dynamic Resolution
MITRE Version
1.1
Last Modified
May 12, 2026

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