T1568.003: DNS Calculation

MITRE ATT&CK® Enterprise technique

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 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)

Detection

(no detection guidance published)

Data sources

• (none listed)

References

• ATT&CK page: https://attack.mitre.org/techniques/T1568/003
• ATT&CK Enterprise matrix: https://attack.mitre.org/matrices/enterprise/