DNS/索引/virustotalについて、ここに記述してください。

http://blog.virustotal.com/2013/04/virustotal-passive-dns-replication.html

Passive DNS replication is a technology which constructs zone replicas without cooperation from zone administrators, based on captured name server responses.

As explained by Merike Kaeo from the Internet Systems Consortium in this presentation, the main idea behind passive DNS is as follows: