Reconnaissance, also known as the information-gathering phase, is a foundational phase of penetration testing. This crucial stage involves systematically collecting data about the target system, network, or organization with the goal of understanding its structure, potential vulnerabilities, and, most importantly, attack surface. Penetration testers employ various techniques and tools to extract valuable information, such as domain names, subdomains, IP addresses, network topology, and publicly accessible services. It is a critical step that mimics the methods adversaries might use and helps organizations proactively strengthen their security posture by identifying and mitigating vulnerabilities before malicious actors can exploit them.
There are various tools available to assist in gathering information about a target. Remember that these tools should always comply with legal and ethical standards and should only be performed on systems you have explicit permission to test.
- theHarvester: A tool for gathering email accounts, subdomains, hosts, employee names, open ports, and banners from different public sources.
- Shodan and Censys: Search engines that allow you to find specific devices, websites, and services connected to the internet.
- DNSDumpster: An online tool that allows you to gather DNS information.
- Fierce: A reconnaissance tool for DNS, designed to locate non-contiguous IP space.
- Whois: The Whois service allows us to access specific information about our target including the IP addresses or host names of the company’s Domain Name Systems (DNS) servers and contact information which usually contains an address and a phone number.
- Netcraft Site Report: The site report provides us with great information about our target including the IP address, OS of the web server, technologies used as well as the DNS server.
- Host: In the phase of reconnaissance, the results sometimes can appear in host names rather than IP addresses. When this occurs, we can use the host tool to deduce the corresponding IP address. In other words, it shows you the corresponding IP address for a given hostname.
- Other tools that can be utilized are nslookup, maltego, Google Hacking Database (GHDB), foca and metagoofil.
Thanks for reading.
Can Özkan
