performing-open-source-intelligence-gathering
Helps your agent collect public information about a target. This is used to better understand the organization before an attack.
What it does
This tool helps gather public information about an organization, such as its domains, employees, and technologies. It's useful for understanding how a target might be attacked.
When to use it
- ✓When testing a company's security.
- ✓When investigating a security incident.
- ✓When planning a security test.
Example of what to ask your AI
“Gather information about the company 'Example Inc.'.”
Want more? Open the sections below.
How to use
The easiest way: copy the message below and paste it into Claude, ChatGPT, Cursor or any AI. It reads the skill and follows the instructions.
Skill link
Ready-to-paste message
How it works
The tool searches for publicly available data from various sources like domain records, social media, and leak databases. It organizes this information to identify weaknesses.
Installation
Easiest way: copy the skill link and paste it into Claude, ChatGPT or Cursor asking it to follow the instructions.
In the terminal (Claude Code, Codex, Cursor), in your project folder:
npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill performing-open-source-intelligence-gatheringOr download just the file:
curl -L https://raw.githubusercontent.com/mukul975/Anthropic-Cybersecurity-Skills/main/skills/performing-open-source-intelligence-gathering/SKILL.md -o SKILL.mdTechnical content (original SKILL.md)
Original text by the author, straight from GitHub.
Performing Open Source Intelligence Gathering
Legal Notice: This skill is for authorized security testing and educational purposes only. Unauthorized use against systems you do not own or have written permission to test is illegal and may violate computer fraud laws.
Overview
Open Source Intelligence (OSINT) gathering is the first active phase of a red team engagement, where operators collect publicly available information about the target organization to identify attack surfaces, potential targets for social engineering, technology stacks, and credential exposures. Effective OSINT directly shapes initial access strategies and reduces operational risk.
When to Use
- When conducting security assessments that involve performing open source intelligence gathering
- When following incident response procedures for related security events
- When performing scheduled security testing or auditing activities
- When validating security controls through hands-on testing
Prerequisites
- Familiarity with red teaming concepts and tools
- Access to a test or lab environment for safe execution
- Python 3.8+ with required dependencies installed
- Appropriate authorization for any testing activities
Objectives
- Enumerate the target organization's external attack surface (domains, IPs, cloud assets)
- Identify employees and their roles for social engineering targeting
- Discover leaked credentials, API keys, and sensitive documents
- Map the organization's technology stack and vendors
- Identify physical locations, office layouts, and access control details
- Build target profiles for spearphishing campaign development
Core Concepts
OSINT Categories
| Category | Sources | Value |
|---|---|---|
| Domain Intelligence | DNS records, WHOIS, CT logs, subdomain enumeration | Network attack surface |
| Personnel Intelligence | LinkedIn, social media, conference talks, publications | Social engineering targets |
| Credential Intelligence | Breach databases, paste sites, GitHub leaks | Valid credential discovery |
| Technology Intelligence | Job postings, Wappalyzer, Shodan, Censys | Vulnerability identification |
| Physical Intelligence | Google Maps, social media photos, Glassdoor | Physical access planning |
| Document Intelligence | SEC filings, public documents, metadata extraction | Organizational structure |
MITRE ATT&CK Mapping
- T1595.001 - Active Scanning: Scanning IP Blocks
- T1595.002 - Active Scanning: Vulnerability Scanning
- T1592 - Gather Victim Host Information
- T1589 - Gather Victim Identity Information
- T1590 - Gather Victim Network Information
- T1591 - Gather Victim Org Information
- T1593 - Search Open Websites/Domains
- T1594 - Search Victim-Owned Websites
- T1596 - Search Open Technical Databases
Workflow
Phase 1: Domain and Network Reconnaissance
- Perform WHOIS lookups for target domains
- Enumerate subdomains using Certificate Transparency logs, DNS brute-force, and web scraping
- Identify IP ranges and ASN ownership
- Scan for exposed services using Shodan/Censys
- Check for cloud storage buckets (S3, Azure Blob, GCS)
- Map CDN and hosting providers
Phase 2: Personnel and Social Intelligence
- Enumerate employees via LinkedIn, company website, and conference speaker lists
- Identify email naming conventions
- Discover personal social media accounts of key targets
- Map organizational hierarchy and reporting structure
- Identify recently hired IT/security personnel
- Check for conference presentations and technical publications
Phase 3: Credential and Data Leak Discovery
- Search breach databases (Have I Been Pwned, DeHashed)
- Check paste sites (Pastebin, GitHub Gists)
- Search GitHub/GitLab for leaked secrets and API keys
- Look for exposed configuration files and backups
- Check for leaked internal documents via Google dorking
Phase 4: Technology Stack Identification
- Analyze job postings for technology mentions
- Use Wappalyzer/BuiltWith for web technology fingerprinting
- Check for exposed admin panels and development environments
- Identify VPN and remote access technologies
- Map cloud services and SaaS applications
Tools and Resources
| Tool | Purpose | Type |
|---|---|---|
| Amass | Subdomain enumeration and network mapping | Open Source |
| Subfinder | Passive subdomain discovery | Open Source |
…
FAQ
What is 'Open Source Intelligence' (OSINT)?
It's collecting information that is already publicly available, without needing to hack into systems.
Do I need permission to use this tool?
Yes, you should only use it on systems you own or have explicit permission to test. Unauthorized use is illegal.
What kind of information does it collect?
It can collect domain names, email addresses, technologies used, potential password leaks, and employee information.
Details
Original description by the author
Open Source Intelligence (OSINT) gathering is the first active phase of a red team engagement, where operators collect publicly available information about the target organization to identify attack s
Popularity
- GitHub stars
- 35k
- Ranking position
- #6112
- License
- Apache-2.0
- Updated
- 8/31/2026
Comments
- …
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