From the Battle of the Little Bighorn to the (fictional) Battle of the Bastards, failures to gather enough intel on enemy positions or terrain have often proved decisive in warfare.
Reconnaissance is every bit as fundamental for finding promising avenues of attack when probing digital systems for vulnerabilities.
Master the art of hacking recon, which involves gathering intelligence about your target system, and you can expand visible attack surfaces and make your hunt more targeted – considerably enhancing your chances of Bug Bounty success.
This all-in-one resource summarises each article that featured in our series on various essential Bug Bounty reconnaissance techniques, such as subdomain enumeration, port scanning, HTTP fingerprinting, hidden-parameter mapping, Google dorking and archive-based recon. These how-to guides also teach you how to unlock high-impact vulnerabilities using popular recon tools such as Nmap, Shodan and the Wayback Machine.
This recon recap consolidates six articles that each tackle a different set of popular methods used by ethical hackers and Bug Bounty hunters to learn about their targets.
Outline
- Recon Series #1: Discovering and mapping hidden endpoints and parameters to expand attack surfaces
- Recon Series #2: Subdomain enumeration – expand attack surfaces with active, passive techniques
- Recon series #3: HTTP fingerprinting – sleuthing for a web application’s hidden vulnerabilities
- Recon series #4: Port scanning – uncovering attack vectors by revealing open ports and hidden services
- Recon series #5: A hacker’s guide to Google dorking
- Recon Series #6: Excavating hidden artifacts with Wayback Machine and other web-archive tools
- Conclusion: Recon is a bedrock for Bug Bounty and footprinting in cybersecurity
Recon Series #1: Discovering and mapping hidden endpoints and parameters to expand attack surfaces
Vulnerabilities often lurk in places that automated scanners typically fail to reach. While security tools excel at finding misconfigurations or known vulnerabilities with signatures, ethical hackers can uncover additional attack surface through manual reconnaissance techniques, such as force browsing for hidden directories, fuzzing for concealed endpoints and meticulously extracting URLs from client-side source code. The first article in our series explains how to manually map hidden assets that might uncover high-impact findings overlooked by researchers who rely more heavily on automation.
Recon Series #2: Subdomain enumeration – expand attack surfaces with active, passive techniques
You can dramatically expand your attack surface by exhaustively discovering all in-scope subdomains. The second instalment in our recon series explains how to map your target’s infrastructure by collecting all related subdomains and organising them within a file or database. This article covers both passive techniques like using public databases and Google dorking as well as active methods like DNS brute-forcing and virtual host fuzzing.
Recon series #3: HTTP fingerprinting – sleuthing for a web application’s hidden vulnerabilities
HTTP fingerprinting involves gathering detailed information about the technologies powering a web application. These cyber recon methods can glean vital intel about programming languages, software versions, firewalls or third-party services. From analysing HTTP headers to performing malformed HTTP requests, this guide explains various techniques for profiling a technology stack in ways that enable you to craft more targeted and effective exploits.
Recon series #4: Port scanning – uncovering attack vectors by revealing open ports and hidden services
Port scanning identifies open ports, running services and service versions on target hosts. By understanding what a host exposes, you can tailor your bug-hunting strategy to precisely target specific weaknesses. This article explores the advantages of different port scanning methods, recommends the most effective tools, and offers practical, real-world examples drawn from Bug Bounty engagements.
Recon series #5: A hacker’s guide to Google dorking
Google dorking (or Google hacking) leverages Google’s advanced search operators to find publicly available information about targets. This footprinting technique is especially effective for detecting information-disclosure issues such as exposed credentials, forgotten admin panels and unsecured services indexed by search engines. Read our Google hacking guide to learn how to craft dorks that yield valuable intel, such as the query site:example.com intitle:"index of" backup, which often reveals publicly accessible backup directories.
Recon Series #6: Excavating hidden artifacts with Wayback Machine and other web-archive tools
The Wayback Machine and similar tools serve as time machines for the internet. For Bug Bounty hunters, web archives can reveal deprecated or forgotten endpoints that may still be reachable and vulnerable, even if they’re no longer actively used by the modern application. The concluding part of our hacking reconnaissance series covers the value of archive-based recon, how to wield logs and snapshots, and some useful commands and tools for eliciting info that might point the way to high-impact vulnerabilities.
Conclusion: Recon is a bedrock for Bug Bounty and footprinting in cybersecurity
Reconnaissance is the vital foundation on which successful Bug Bounty hunts are built. The more you know about your target, the more potential entry points you can identify and exploit.
Throughout this series, we’ve explored essential ethical hacking reconnaissance techniques for uncovering hidden assets, forgotten subdomains, exposed services and other valuable intelligence about in-scope systems. Learn at least the basics of all these Bug Bounty recon methodologies and you can build a powerful reconnaissance workflow to suit a wide range of scopes and contexts.