What is Censys?
Censys is an open-source internet-wide scanning and monitoring platform developed by researchers at the University of Michigan. It offers a comprehensive view of the digital landscape by continuously scanning and indexing internet-connected devices and services. Censys enables users to explore and analyze the vast troves of data it collects, making it a valuable resource for cybersecurity investigations, network monitoring, and digital research.
Before we embark on our journey into the world of Censys, let’s start with the installation process. Censys offers both a web-based interface and command-line tools for accessing its data. In this guide, we’ll focus on installing and using the Censys command-line tool, “censys-cli.”
Ensure you have the following prerequisites before proceeding:
- Python: Censys is a Python-based tool. You’ll need Python 3.x installed on your system. You can download Python from the official Python website.
- PIP: PIP is Python’s package manager and is usually included with Python installations. If it’s missing, you can install it separately.
Follow these steps to install the Censys command-line tool, “censys-cli”:
- Install Censys CLI:Open your terminal or command prompt and run the following command to install “censys-cli” using pip:bash
pip install censys-client
Authenticate with Censys:
To use Censys, you’ll need to authenticate with your Censys API credentials. If you don’t have an account, you can sign up for one on the Censys website.
Once you have your API credentials, configure “censys-cli” by running:
censys config setFollow the prompts to enter your Censys API ID and API secret.
Now that you have “censys-cli” installed and configured, let’s explore how to use it for digital reconnaissance and research.
Here are some basic commands to get you started with “censys-cli”:
- Search for Hosts:You can search for internet-connected hosts using the following command:bash
censys search <query>
<query> with your search query. For example, to search for hosts running the SSH service:
censys search 'services.service_name: "ssh"'
View Host Details:
To view detailed information about a specific host, use the following command:
censys view <ip_address>
<ip_address> with the IP address of the host you want to investigate.
You can export search results in various formats, such as CSV or JSON, using the
--format option. For example, to export results in CSV format:
censys search 'services.service_name: "http"' --format csv > http_hosts.csv
Censys offers advanced features for more in-depth exploration:
- Data Analysis: You can perform advanced queries using Censys’ query language to filter and analyze internet-connected devices and services based on specific criteria.
- Certificates: Censys also indexes SSL/TLS certificates, making it useful for certificate-related research and monitoring.
- Monitoring: Censys offers monitoring capabilities to track changes in internet-connected devices and services over time.
- Integration: You can integrate Censys data into your own applications and workflows using the Censys API.
Responsible Use of Censys
It’s essential to use Censys responsibly and within legal and ethical boundaries:
- Privacy: Respect the privacy of internet-connected devices and services you analyze. Avoid intrusive or unauthorized scanning.
- Legal Compliance: Ensure that you comply with local laws and regulations when conducting internet-wide scanning and research.
- Ethical Research: Use Censys for legitimate purposes such as cybersecurity investigations, network monitoring, and digital research.
Censys is a powerful tool for illuminating the digital landscape, providing insights into internet-connected devices and services. By following the installation steps and understanding how to use “censys-cli” effectively, you can embark on a journey of digital reconnaissance and research. Happy exploring!