Performing Regex Searches Against DNSDB MTBL Files

This article demonstrates how to use DNSDB Export’s local MTBL data with dnstable_dump and grep to perform mid-string searches for brand protection, using “citibank” as an example to extract, de-duplicate, and review related domains before filtering ownership via bulk WHOIS. It outlines a practical workflow (including jq and helper scripts), cautions against directly visiting potentially malicious domains, and notes Farsight’s Brand Sentry for real-time monitoring.