T1568.001sub-technique of T1568 Dynamic Resolution
Fast Flux DNS
Linux · macOS · Windows · ESXinothing on this site yetT1568.001 on attack.mitre.org
Adversaries may use Fast Flux DNS to hide a command and control channel behind an array of rapidly changing IP addresses linked to a single domain resolution. This technique uses a fully qualified domain name, with multiple IP addresses assigned to it which are swapped with high frequency, using a combination of round robin IP addressing and short Time-To-Live (TTL) for a DNS resource record.
how MITRE says to see it
Detection Strategy for Dynamic Resolution using Fast Flux DNS
- Identify repeated DNS resolutions where the same domain name returns multiple IPs in short succession, combined with low TTL values and high query volume from unusual processes. Correlate with process lineage (e.g., Office apps spawning abnormal DNS lookups).
- Monitor resolver logs and auditd events for domains resolving to a rotating set of IPs within very short TTL intervals. Correlate high query rates from non-browser applications (e.g., python, curl).
- Use unified logs to identify processes issuing repeated DNS queries where the resolved IP addresses change frequently within very short TTL values. Correlate with outbound network traffic to validate C2-like patterns.
- Monitor ESXi syslog and esxcli outputs for abnormal DNS resolver behavior, such as frequent domain-to-IP changes or unauthorized modifications of DNS settings used by management agents. Correlate domain lookups with short TTL values.