What is Reconnaissance in Cybersecurity?
When it comes to reconnaissance, there is no other concept in cybersecurity that is as foundational when it comes to understanding and mitigating security threats effectively.
There are many situations and contexts where reconnaissance may be needed including:
• identifying vulnerabilities in a target’s systems, network, or infrastructure
• carrying out threat intelligence and gathering information about potential adversaries’ tactics, techniques, and procedures (TTPs)
• assessing the risk associated with a particular infrastructure
• strategic decision-making
This post aims to demystify this key concept further whilst providing insight into the best online and programming tools that can help with the job. Read on to learn more.
‘Recon’, a process
Reconnaissance in cybersecurity, often referred to as “cyber reconnaissance” or simply “recon,” is the process of gathering information about a target system, network, or organization to identify vulnerabilities, potential attack vectors, and other relevant details. It is the initial phase of a cyber attack and is typically conducted by threat actors or security professionals to assess the security posture of a target.
The primary goals of reconnaissance are as follows:
1. Information Gathering: Reconnaissance involves collecting data about the target, such as IP addresses, domain names, network topology, system configurations, software versions, and potential security weaknesses.
2. Target Identification: Attackers aim to identify specific targets within a network or organization, such as valuable data, servers, or critical infrastructure.
3. Vulnerability Assessment: By analyzing the gathered information, individuals can identify potential vulnerabilities and weaknesses in the target’s systems and applications. This information can be used to plan further stages of an attack.
As ethical hackers, it is often important that no sign of recon is visible to any target being looked at. This is where it is key to think about how we are interacting as well as why. Due to the varying methods we have in our toolkit, we can actually split reconnaissance into two further main types:
1. Passive Reconnaissance:
Here we are collecting information without directly interacting with the target. It often includes activities like searching for publicly available information on websites, social media, and publicly accessible databases. Passive reconnaissance is less likely to raise suspicions since it doesn’t involve direct interaction.
2. Active Reconnaissance:
Active reconnaissance involves more direct probing of the target, such as scanning for open ports, running vulnerability scans, or attempting to interact with the target system. This approach is riskier for threat actors, as it may trigger intrusion detection systems and alert the target to activities.
Online tools:
There are many online tools and services that can be used for reconnaissance in cybersecurity. These tools are often web-based and can assist in gathering information about a target’s online presence and potential vulnerabilities. Here are some of the top online tools for reconnaissance:
1. Shodan (https://www.shodan.io): Shodan is a popular online search engine that allows you to find and discover internet-connected devices, services, and open ports. It’s particularly useful for identifying exposed devices and potential security issues.
2. Censys (https://censys.io): Censys is another internet-wide search engine that provides data on exposed services and devices. It allows you to search for and analyze internet assets.
3. SecurityTrails (https://securitytrails.com): SecurityTrails provides domain and IP address intelligence, including historical DNS data, subdomain discovery, and SSL/TLS certificate information.
4. Spyse (https://spyse.com): Spyse is an online search engine for finding information about internet assets, including domains, IP addresses, open ports, and SSL certificates.
5. ViewDNS.info (https://viewdns.info): ViewDNS.info offers various online tools for DNS reconnaissance, such as DNS lookups, reverse DNS lookups, and domain research.
6. VirusTotal (https://www.virustotal.com): VirusTotal allows you to check files, URLs, and IP addresses for potential malicious activity. It aggregates data from various antivirus engines and threat intelligence sources.
7. BuiltWith (https://builtwith.com): BuiltWith helps you discover the technologies used by websites. It provides information about web server software, content management systems, frameworks, and more.
8. ThreatConnect (https://www.threatconnect.com): ThreatConnect is a threat intelligence platform that provides information on malicious indicators, threat data, and associated domains and IP addresses.
These online tools can be valuable resources for conducting reconnaissance and gathering information about potential security issues. However, it’s essential to use them responsibly and within the bounds of the law, respecting privacy and compliance requirements. Always ensure that you have the appropriate authorization to perform reconnaissance on a target.
Programming Tools:
For a more effective reconnaissance process, programming tools are also often used to automate and customize activities to gather and analyze information about a target. These tools allow security professionals, penetration testers, and ethical hackers to tailor their reconnaissance efforts to specific needs. Here are some of the top programming tools and libraries for reconnaissance in cybersecurity:
1. Python: Python is a versatile and widely used programming language in the cybersecurity field. It provides numerous libraries and modules for building custom reconnaissance scripts and tools.
— Requests: A Python library for making HTTP requests, allowing you to interact with websites and web services.
— Beautiful Soup: Used for web scraping and parsing HTML, making it valuable for extracting data from web pages.
— Scapy: A powerful library for packet manipulation, making it suitable for network reconnaissance and analysis.
— Sublist3r: A Python tool for finding subdomains associated with a target domain.
2. Ruby: Ruby is another programming language that can be used to create custom reconnaissance tools.
— Metasploit Framework: While primarily known for its exploitation capabilities, Metasploit can also be used for information gathering and reconnaissance.
3. Go: The Go programming language is gaining popularity in cybersecurity due to its efficiency and performance. Several Go libraries and frameworks can be used for reconnaissance:
— Amass: An open-source tool for discovering subdomains, IP addresses, and other network information.
— HTTPProbe: A tool for probing HTTP and HTTPS services for information and potential vulnerabilities.
4. Node.js: Node.js is a runtime environment that allows you to build server-side applications using JavaScript. It can be used for web-related reconnaissance tasks, such as web scraping and API interaction.
— Puppeteer: A Node.js library for automating web browser tasks, useful for web application reconnaissance and data extraction.
5. PowerShell: In Windows environments, PowerShell is a powerful scripting language that can be used for various reconnaissance tasks.
— PowerShell Empire: An open-source post-exploitation framework that includes reconnaissance modules for information gathering.
6. Scikit-learn (Python): Scikit-learn is a Python library for machine learning and data analysis. It can be used to analyze and classify data collected during reconnaissance for pattern recognition and threat detection.
7. Libraries for API Interaction: Many programming languages provide libraries for interacting with APIs, which can be be useful for reconnaissance when collecting data from online services or social media platforms.
— For Python: libraries like `requests`, `tweepy` (Twitter API), `facebook-sdk`, etc.
— For Go: libraries like `github.com/google/go-github` (GitHub API), `github.com/dghubble/go-twitter` (Twitter API), etc.
These programming tools and libraries allow cybersecurity professionals to create custom scripts and tools tailored to their specific reconnaissance needs. When using these tools, it’s essential to do so within the bounds of ethical and legal standards and to obtain proper authorization for conducting reconnaissance on any target.
Additional tools:
- Nmap
- Recon-ng
- theHarvester
- Maltego
- Google Dorks
- Nikto
- Wireshark
In summary, reconnaissance plays a critical role in helping organizations and security professionals stay ahead of cyber threats. It empowers them to make informed decisions, assess risks, and implement effective security measures to protect their digital assets and data.
With some dedicated time to learn some of the tools listed above you can too.
Additional Resources:
To explore the broad topic of reconnaissance further I recommend you check out some of the links or resources below. Thanks for reading.
Books:
- Open Source Intelligence Techniques: Resources for Searching and Analyzing Online Information
- Nmap Network Scanning: The Official Nmap Project Guide to Network Discovery and Security Scanning” by Gordon Fyodor Lyon
- Metasploit: The Penetration Tester’s Guide” by David Kennedy, Jim O’Gorman, Devon Kearns, and Mati Aharoni
Videos:
Sites:
Remember to stay ethical and within legal boundaries when conducting reconnaissance activities, and always ensure that you have the proper authorization to perform any assessments.
