Graylog3 supported

Content Pack for piHole with Graylog

Built and based off of https://jalogisch.de/2017/der-eigene-dns-resolver-zuhause/, your own dns resolver (at home) by Jan Doberstein. Includes setting GeoIP, so ensure you download the current City db from Maxmind, and install the current Threat intelligence content packs. A seperate input is established to collect only pihole syslog traffic.

Syslog requirements

syslog-ng Best option, simple and only sends pihole data

#apt install syslog-ng -y
#vi /etc/syslog-ng/conf.d/10-pihole.conf
source s_pihole_log { file("/var/log/pihole.log"); };
destination d_graylog {udp("server.ip" port(1515)); };
log { source(s_pihole_log); destination(d_graylog); };

Content Pack includes:

• GROK patterns:
  Defines all new fields to be set when matched in pipeline

  • DNSMASQ
  • PIHOLE

• Input:
  Sets a seperate input for just pihole DNS Logs

  • piHole Syslog (Listen 0.0.0.0:1515/UDP)

• Extractor:

  • application_name (Looking for pihole)

  This extractor is contingent on how you implemented your data ingestion of pihole and can be unreliable a times. Recommended correction is to delete the extractor from your input, and update the pipeline rules for dnsmasq pihole list & dnsmasq split. The when condition should be changed from has_field("application_name") to contains(to_string($message.source),"IP") where IP is the IP of your pihole server.

• Pipeline:
  Creates Multiple fields to enable stronger queries and analytics

  • -1 Rules:
    • dnsmasq pihole list
    • dnsmasq split
  • 0 Rules:
    • PiHole GeoIP Set
  • 1 Rules:
    • threatintel (dnsmasq)
    • dnsmasq clean message
  • 2 Rules:
    • threatintel (2) inflate

• Lookup Table\Cache:

  • geolite2-city (/etc/graylog/server/GeoLite2-City.mmdb)

• Dashboard called DNS Intel:

  • DNS Location Requested IP (from answers)
  • DNS Activities (24h)
  • Thread Names (24h)
  • Blocked Domains (24h)
  • Blackholed Requests (24h)
  • Threat Indicated (24h)
  • DNS Clients (24h)
  • DNS Querys (24h)
  • Owning Companies (24h)