John, a professional hacker, decided to use DNS to perform data exfiltration on a target network, in this process, he embedded malicious data into the DNS protocol packets that even DNSSEC cannot dete

DNS cache snooping is a passive reconnaissance technique used to infer which domains a resolver has recently queried by checking TTL values, not a method for injecting malware or bypassing firewalls.

DNSSEC zone walking exploits NSEC records to enumerate all domain names within a signed DNS zone, which is a reconnaissance technique and does not involve data exfiltration or covert C&C channels.

DNS tunneling encapsulates non-DNS payloads such as malware commands or exfiltrated data inside DNS query and response fields, exploiting the fact that most firewalls permit DNS traffic on port 53 - because the data is embedded within structurally valid DNS packets, DNSSEC cannot detect it since DNSSEC only validates DNS record integrity and authenticity, not the semantic content of payloads.

DNS enumeration is a reconnaissance method for discovering DNS records (A, MX, NS, CNAME, etc.) associated with a target domain, not a technique for bypassing firewalls or maintaining covert communication.