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ActiveDNS

An active domain name query tool to help keep track of domain name movements...

A tool to activly collect DNS records to aid Security Analysts tracking threats.

ActiveDNS activly resolves domain names and outputs the DNS-server answers to a log file. ActiveDNS cache/aggregate the TTL responses for each domain in memory and does not try to resolve the domains again before the TTL has expired. This also limits the log file for unnecessary duplicates.

ActiveDNS can also save the state of when to resolve a domain again, so it will request to a minimum even on a restart. It also supports reloading the list of domains to query without having to restart ActiveDNS.

The logformat is compatible with the logformat of PassiveDNS.

Example output from the log file (/var/log/activedns.log):

timestamp||dns-client ||dns-server||RR class||Query||Query Type||Answer||TTL||Count 1322849924.123456||192.168.0.1||8.8.8.8||IN||upload.youtube.com.||A||74.125.43.117||46587||1 1322849924.123456||192.168.0.1||8.8.8.8||IN||upload.youtube.com.||A||74.125.43.116||420509||1 1322849924.123456||192.168.0.1||8.8.8.8||IN||www.adobe.com.||CNAME||www.wip4.adobe.com.||43200||1 1322849924.123456||192.168.0.1||8.8.8.8||IN||www.adobe.com.||A||193.104.215.61||43200||1 1322849924.123456||192.168.0.1||8.8.8.8||IN||i1.ytimg.com.||CNAME||ytimg.l.google.com.||43200||1 1322849924.123456||192.168.0.1||8.8.8.8||IN||clients1.google.com.||A||173.194.32.3||43200||1

ActiveDNS uses Net::DNS::Async which makes it possible to query a lot of domains really fast.

** How can ActiveDNS be used: **

Typical usages:

1. Keep track of domain or IP history when working on incidents. Example: Your company has been hit with a repated email phising attack. The CC of the malware that is installed (if anyone falls for the attack) has been using domains: bot1.mybots.info, bot2.mybots.info, newbot.mybots.info

   Keeping a track of the domains and what IP it resolves to, gives you an idea of what IPs the attacker might be in control of.

   Activly resolving the domains, reveals that for a small time period each monday, the attackers point the domains to a IP you have not seen before. Quering your NetFlow data, reveals that some of your machines acctually talked to that IP within the small periode it resolved to this IP. Digging further in your PassiveDNS logs, you find that the host talking to that IP, resolved the domain: badbot.hiddenbots.com

   Looking at PassiveDNS for the domain badbot.hiddenbots.com shows that this domains points to a new parking IP that you where not aware of, and you find from your PassiveDNS logs more domains pointing to that parking IP that seems to be related.

Questions, suggestions, sugar or flame is always welcome :)

I hope ActiveDNS gives you a new tool to fight malware and its herders...

(c)2013 - Edward Bjarte Fjellskål