A tool to collect DNS records passively to aid Incident handling, Network
Security Monitoring (NSM) and general digital forensics.

PassiveDNS sniffs traffic from an interface or reads a pcap-file and outputs
the DNS-server answers to a log file. PassiveDNS can cache/aggregate duplicate
DNS answers in-memory, limiting the amount of data in the logfile without
losing the essense in the DNS answer.

WWW: https://github.com/gamelinux/passivedns