Quick Start
Censys Legacy Search empowers users with the most comprehensive, accurate, and up-to-date map of the Internet for proactive and reactive security analysis at scale. Follow the steps below to get started.
For information on using Legacy Search via the API, please see Censys Legacy Search API Quickstart Guide.
Go to search.censys.io
Start your journey on the Legacy Search main page.
Search with example queries
To get started quickly, try running some of the example queries listed below.
Example host queries
| Query description | Query syntax |
|---|---|
| Hosts with exposed RDP services | services.service_name=RDP |
| Hosts in China | location.country=China |
| Hosts running services using a specific JA4S fingerprint | services.tls.ja4s: t130200_1303_a56c5b993250 |
| Hosts running SSH on a nonstandard port | services: (service_name: SSH and not port: {22, 2222}) |
Example certificate queries
| Query description | Query syntax |
|---|---|
| Certificates with "censys.io" anywhere in their name data and the "unexpired" label | names="censys.io" and labels=unexpired |
| Certificates revoked in the last 24 hours | revocation.crl.revocation_time: [now-24h TO now] |
Build queries
Switch between host or certificate datasets
Click Hosts next to the query bar to switch between targeting host or certificate datasets.
Input search criteria
Click in the search text field and start typing. Keyword syntax matching your input appears. To target a specific data field, select the item you want to use. All data definitions for hosts and certificates are available in the web interface.
Learn more about writing queries here.
Modify your search
In the search bar, click to configure your sort order, the number of results per page, and whether to exclude, include, or only target virtual hosts when searching across the host dataset.
Refine your queries
Using the examples as a starting point, refine your queries with values relevant to your investigations.
You can also use the click-to-search button in the raw data table view of any certificate or host record to launch a search for something you are interested in.
Use AI to refine queries
CensysGPT (Beta) simplifies query building and empowers efficient and effective reconnaissance operations. It can quickly and easily provide insights into internet hosts, streamlining the process and allowing for more proactive threat hunting and attack surface management.
Understand your search results
Review host search results
The search results show a list of hosts and virtual hosts matching your query, including the IPv4 or IPv6 address, autonomous system (AS) and geographic location, number of services matching the query, port number or service name, and other services on the host.
Review certificate search results
The search results show a list of certificate records matching the query, including the distinguished name (DN) of the certificate's subject, the DN of the certificate's issuer, the validity start and end dates, and names from all sections of the certificate.
Generate reports
After conducting a search in Censys, you can generate a report on the breakdown of a value present on the Hosts returned by your query. To create a report, click the Report tab on the upper right side of the results page.
Additional resources
To make the most out of your searches, we recommend reviewing the following resources:
- Censys Search Language
- This documentation explains the Censys Search Language syntax.
- Cooking up Queries: Your Guide to Savory Internet Searches
- In this ebook, find queries for discovering critical infrastructure, rapid responses to zero days, finding hacked web servers, uncovering ransomware, and more.
- Legacy Search API Quickstart Guide
- The Legacy Search API allows you to integrate Censys data into your applications, scripts, or security tools.
- Legacy Search Release Notes
- Follow the release notes to stay up to date on the latest product changes and enhancement
Updated 15 days ago