Search engines are incredible tools for finding information online, but they can also be used by attackers for reconnaissance.
How Attackers Use Search Engines for Reconnaissance
Search engines like Google and Bing provide a vast amount of information that attackers can exploit. By using specific search commands, they can uncover sensitive data, find vulnerabilities, and prepare for attacks.
Google Hacking Database (GHDB):
The Google Hacking Database (GHDB) is a collection of search queries that help find vulnerabilities and sensitive data exposed by websites. It's a valuable resource for attackers and can be found on the Exploit Database website.
Key Search Commands Attackers Use
site: Searches a specific domain. Example: site: example.com restricts the search to example.com.
link: Finds websites linking to a specific page. Example: link: example.com shows all sites linking to example.com.
intitle: Searches for pages with specific words in the title. Example: intitle: "login page" finds pages with "login page" in the title.
inurl: Looks for URLs containing specific words. Example: inurl: admin finds URLs with "admin" in them.
related: Finds pages related to a specific URL. Often less useful but can sometimes uncover valuable information.
cache: Accesses the cached version of a webpage stored by Google. Example: cache: example.com shows Google's cached copy of example.com.
filetype/ext: Searches for specific file types. Example: filetype: pdf or ext: pdf finds PDF files, useful for locating documents that might contain sensitive information.
Practical Reconnaissance Techniques
1. Searching for Sensitive Files: Attackers search for files that might be accidentally exposed, such as:
Web Content: site: example.com asp, site: example.com php
Document Files: site: example.com filetype: xls, site: example.com filetype:pptx
2. Using Cache and Archives:
Google Cache: Retrieves recently removed pages using the cache: command.
Wayback Machine: Archives webpages over time, available at archive.org.
3. Automated Tools:
FOCA/GOCA: Finds files, downloads them, and extracts metadata, revealing usernames, software versions, and more.
SearchDiggity: Provides modules for Google, Bing, and Shodan searches, malware checks, and data leakage assessments.
Recon-ng: A framework that queries data from multiple services and manages data across projects.
Conclusion
Search engine reconnaissance is a powerful tool for attackers, providing them with a wealth of information to plan their attacks. By understanding these techniques and implementing robust defensive measures, you can significantly reduce your exposure and protect your critical data. Stay vigilant, stay informed, and continuously audit your public-facing assets to maintain a strong security posture.
Akash Patel