Security Professionals can use Passive DNS to investigate domains or IP addresses that have raised suspicion, and find out if it is a single malicious IP or a complex multi-layered operation they are dealing with.

  • Investigate domains that are within the same subnet of a particular IP address – some (or most) of these may display similar behaviours as the one that has caused you concern.
  • Abusers recycle their resources e.g. the same web server may host several phishing domains, not just one. With Passive DNS you can acquire the information before, or as soon as they change their domain or IP address.
  • If you are dealing with a more complex operation, the abuser may have the full /24 subnet under his control and Passive DNS can potentially provide additional, deeper insights e.g. all the domains that are pointing to an IP address in the subnet.
  • Passive DNS searches will also permit you to find invalid or unauthorised records in the zones you control, caused by unauthorised access or by cache poisoning/spoofing (where corrupt DNS data is introduced into the DNS resolver’s cache, causing the name server to return an incorrect result).

Sign up to a Free Passive DNS Account here.

Passive DNS

Our Passive DNS allows you to quickly and easily navigate through billions of DNS records to shine a spotlight on potentially malicious internet resources associated with your network or domain.

  • Reduce investigation times
  • Protect your online brand
  • Protect customers and end-users

WEBINAR | Rapid investigation into potential threats with Passive DNS

29 September 2020


Analyzing your network, and beyond, for potential cyber threats is hugely time-consuming. However, utilizing Passive DNS data can quickly highlight possible issues. Spamhaus' Head of Data, Carel Bitter and Industry Liaison, Matthew Stith walk you through real-life scenarios to demonstrate how Passive DNS can help you.

Spamhaus Technology showcases new threat detection tool at GovWare

17 September 2018


Spamhaus launches its Passive DNS tool at GovWare 2018 in Singapore.