Why Do Incident Responders and Other Investigators Focus on Particular DNS Record Types?

**Executive Summary:** This blog post explains how analysts leverage passive DNS (DNSDB) to prioritize and pivot on DNS record types—primarily A/AAAA/CNAME and NS—illustrating common investigative workflows (wildcard domain searches, IP-to-name pivots, NS-based lateral pivots), command examples (dnsdbq and jq), and notable indicators that draw attention (algorithmic/random-looking domains, unusually large SPF CIDR ranges, use of NULL records for tunneling), with a reminder to explicitly query DNSSEC records when needed.