Skill: Open Source Intelligence (OSINT)

Supplementary Files:

• payloads.md — OSINT attack payloads and command collection (domain reconnaissance, DNS enumeration, subdomain discovery, Google Dorking, email collection, social media intelligence, metadata extraction, Shodan/Censys queries, leaked data queries, technology fingerprinting)
• test-cases.md — Structured test cases (passive reconnaissance, active scanning, OSINT collection, technology fingerprinting) with severity levels and summary tables

Summary

Osint skill domain covering osint operations.

Domain: osint

MITRE ATT&CK: TA0043-Reconnaissance

Description

A specialized skill for intelligence gathering using publicly available sources. OSINT is a core capability in the reconnaissance phase of penetration testing, covering comprehensive information acquisition from domains, emails, and usernames to social media, leaked data, and threat intelligence. This skill focuses on 13 professional OSINT tools and 5 major practical workflows, emphasizing passive collection, compliant operations, and cross-verification.

Difference from the recon-osint skill: recon-osint focuses on active reconnaissance (port scanning, directory brute forcing, web fingerprinting), while this skill focuses on passive intelligence gathering (no direct interaction with the target).

Use Cases

• Pre-engagement passive reconnaissance for penetration testing: Build a complete intelligence profile before touching the target system
• Red team exercise personnel intelligence: Collect target organization employee emails, social accounts, and technology stacks
• Email and credential breach checking: Check if target emails appear in data breaches
• Cross-platform username tracking: Search for specific usernames across 300+ social platforms
• Threat intelligence and attack surface assessment: Discover exposed assets through Shodan, Certificate Transparency, etc.
• Social engineering information preparation: Collect publicly available information about target personnel for phishing exercise preparation

Core Tools

Comprehensive Frameworks

Tool	Purpose	Command Example
SpiderFoot	Automated OSINT collection (200+ modules)	spiderfoot -s target -t ALL -u passive
Recon-ng	Modular web reconnaissance framework	recon-ng > use recon/domains-hosts/brute_hosts
Maltego	Visual link analysis	GUI: Domain -> DNS Names -> IP Address
sn0int	Semi-automated structured OSINT	sn0int workspace create osint_test

Email and Personnel Intelligence

Tool	Purpose	Command Example
theHarvester	Email, subdomain, and personnel collection	theHarvester -d example.com -b all
h8mail	Email breach query (20+ data sources)	h8mail -t target@email.com
Holehe	Email registration detection across 120+ services	holehe target@email.com

Username and Social Media

Tool	Purpose	Command Example
Sherlock	Username search across 300+ platforms	sherlock username --json

Network and Device Intelligence

Tool	Purpose	Command Example
Shodan	IoT and server search engine	shodan host <IP>
PhoneInfoga	Phone number intelligence collection	phoneinfoga -n +1234567890 -s all

Code and Credentials

Tool	Purpose	Command Example
GitHub Dorking	GitHub sensitive information search	curl -s "https://api.github.com/search/code?q=..."
Git-Dumper	Offline Git repository download and analysis	git-dumper https://github.com/user/repo /output

Methodology

OSINT Five-Phase Process

Phase 1: Passive Collection

No direct interaction with the target; use only public data sources.

# WHOIS domain registration information
whois example.com

# DNS record collection
dig any example.com @8.8.8.8
subfinder -d example.com -o subdomains.txt
dnsx -d example.com -a -silent

# Certificate Transparency query
theHarvester -d example.com -b crtsh

# Search engine passive collection
theHarvester -d example.com -b google

# SpiderFoot fully automated passive scan
spiderfoot -s example.com -t INTERNET_NAME,DNS_ANY,SUBDOMAIN_HTTPS -u passive

Phase 2: Email Intelligence

Collect target organization emails and check for breaches.

# Email collection (multiple data sources)
theHarvester -d example.com -b all

# Email format inference
theHarvester -d example.com -b hunter

# Breach checking
h8mail -t user@example.com
h8mail -t @targetdomain.com -l local

# Service registration detection
holehe user@example.com

# PGP key search
gpg --search-keys user@example.com

Phase 3: Username and Social Media

Track target usernames across major platforms.

# Cross-platform username search
sherlock username1 username2 --json

# LinkedIn employee search
theHarvester -d "Company Name" -b linkedin

# Twitter association
theHarvester -d example.com -b twitter

Phase 4: Domain and Asset Discovery

# Subdomain enumeration (multi-tool cross-verification)
subfinder -d example.com -o subs_subfinder.txt
amass enum -passive -d example.com -o subs_amass.txt

# Merge, deduplicate, and verify
sort -u subs_*.txt | httpx -silent -status-code -title

# DNS brute force
gobuster dns -d example.com -w /usr/share/wordlists/subdomains-top1mil-20000.txt

# Shodan search for exposed devices
shodan search "org:Example Corp"
shodan host <IP>

Phase 5: Credential and Code Leak

# GitHub sensitive information search
curl -s "https://api.github.com/search/code?q=org:company+password+in:file"
curl -s "https://api.github.com/search/code?q=user:username+api_key+in:file"
curl -s "https://api.github.com/search/code?q=repo:owner/repo+secret+in:path"

# Breach database query
curl "https://haveibeenpwned.com/api/v3/breachedaccount/<EMAIL>"

# Offline repository analysis
git-dumper https://github.com/user/repo /tmp/repo_analysis
grep -r "password\|api_key\|secret\|token" /tmp/repo_analysis/

Quick Selection Guide

Scenario	Primary Tool	Alternative
Quick comprehensive scan	SpiderFoot	Recon-ng
Email collection	theHarvester + Hunter	h8mail
Email breach check	h8mail	HaveIBeenPwned API
Email registration detection	Holehe	--
Username tracking	Sherlock	Namechk
Phone number intelligence	PhoneInfoga	--
Subdomain enumeration	subfinder + amass	dnsenum, fierce
Device search	Shodan	Censys
Code leakage	GitHub Dorking	Git-Dumper
Visual correlation	Maltego	--
Automation pipeline	Recon-ng	sn0int

Defense Perspective

• OpSec Awareness: Regularly use Sherlock and h8mail to check your own information exposure
• Breach Monitoring: Subscribe to HaveIBeenPwned notifications for timely detection of credential leaks
• Code Auditing: Scan organization GitHub repositories for sensitive information (API keys, passwords)
• Subdomain Governance: Regularly clean up abandoned DNS records to prevent subdomain takeover
• Employee Training: Minimize social media exposure, avoid leaking technology stacks and internal information

Practical Steps

Practical Exercise 1: Complete Intelligence Profile of Target Organization

# Step 1: Domain basic information
whois example.com
dig any example.com @8.8.8.8

# Step 2: Email and personnel collection
theHarvester -d example.com -b all -f recon_report.html

# Step 3: Breach checking
h8mail -t @example.com -o leaks.json

# Step 4: SpiderFoot comprehensive scan
spiderfoot -s example.com -t ALL -u passive -o json > full_osint.json

# Step 5: Visual correlation (Maltego)
# Domain -> DNS Names -> IP -> AS Number -> Organization

Practical Exercise 2: Target Personnel Social Tracking

# Step 1: Collect employee emails
theHarvester -d example.com -b linkedin

# Step 2: Extract usernames and search across platforms
sherlock user1 user2 user3 --json -o social_accounts.json

# Step 3: Email service association
holehe user@example.com

# Step 4: Phone number intelligence
phoneinfoga -n +1234567890 -s all

Practical Exercise 3: GitHub Code Leak Audit

# Step 1: Search for organization sensitive files
curl -s "https://api.github.com/search/code?q=org:target+filename:.env" | jq '.items[].html_url'
curl -s "https://api.github.com/search/code?q=org:target+password+in:file" | jq '.items[].html_url'

# Step 2: Search for key credential keywords
for keyword in password secret api_key token private_key aws_access_key; do
  curl -s "https://api.github.com/search/code?q=org:target+${keyword}+in:file" | jq '.items[].html_url'
done

# Step 3: Download suspicious repositories for in-depth analysis
git-dumper https://github.com/target/suspicious-repo /tmp/audit
grep -rn "password\|api_key\|secret\|token\|aws_" /tmp/audit/ --include="*.yml" --include="*.env" --include="*.json"

Practical Exercise 4: Recon-ng Automation Pipeline

# Launch and create workspace
recon-ng
[recon-ng] > workspaces create target_recon

# Add target domain
[recon-ng] > add domains example.com

# Subdomain enumeration module chain
[recon-ng] > use recon/domains-hosts/brute_hosts
[recon-ng] > run
[recon-ng] > use recon/hosts-hosts/resolve
[recon-ng] > run

# Email collection
[recon-ng] > use recon/domains-contacts/email-harvester
[recon-ng] > set source example.com
[recon-ng] > run

# Export results
[recon-ng] > show hosts
[recon-ng] > show contacts
[recon-ng] > export csv /tmp/recon_results.csv

For detailed payloads see payloads.md, and for the complete test checklist see test-cases.md.

Online OSINT Resources

Search Engines and Devices

Resource	Purpose
Google advanced operators	site:, inurl:, filetype:, intitle:
Shodan (shodan.io)	IoT device and server search
Censys (censys.io)	Certificate and host data
Yandex	Image reverse search (strong recognition capability)

Domain and DNS

Resource	Purpose
WHOIS (whois.domaintools.com)	Domain registration information
crt.sh	Certificate Transparency query
DNSdumpster	DNS enumeration
VirusTotal	URL/domain analysis

Email and Breaches

Resource	Purpose
Hunter.io	Email lookup and format inference
HaveIBeenPwned	Breach checking
DeHashed	Breach database search
LeakCheck	Breach checking

Threat Intelligence

Resource	Purpose
AlienVault OTX	Open-source threat intelligence
AbuseIPDB	IP report query
GreyNoise	Internet noise filtering
IPinfo	IP geolocation and ownership query

Business Information (China)

Resource	Purpose
Tianyancha	Enterprise information query
Qichacha	Enterprise business registration information
Aiqicha	Baidu enterprise query

Safety Notes

• Use VPN or Tor: Avoid exposing your real IP
• Set request intervals: Avoid triggering target protection and rate limiting
• Compliant operations: Only scan authorized targets, comply with local laws and regulations
• Encrypted data storage: Encrypt sensitive intelligence, regularly clean up temporary files
• Harmless User-Agent: Use common browser UAs to avoid being identified as a scanner

Detection Methods

OSINT detection focuses on identifying reconnaissance activity from external sources and monitoring what information about your organization is publicly available. Understanding attacker reconnaissance patterns helps defenders deploy decoys and detect intelligence-gathering activity.

Network-Level Indicators (Defender Perspective)

• Certificate Transparency monitoring: New SSL certificates issued for typosquatted or subdomains of your brand (use crt.sh alerts, CertSpotter).
• DNS enumeration patterns: Spike in ANY queries, AXFR attempts, or DNS brute forcing (subfinder, amass, gobuster signature).
• Shodan / Censys exposure: Regular export of your org's exposed services from Shodan/Censys; alert on new open ports or services.
• Search engine dorking: Google / Bing searches containing site:yourdomain.com filetype:pdf inurl:admin; monitor Google Search Console for suspicious query patterns.
• WHOIS lookups: Spike in WHOIS queries for your domain from non-trusted resolvers.

Web Infrastructure Indicators

• Subdomain takeover monitoring: Regular subjack / nuclei takeover scans of own infrastructure; alert on dangling DNS pointing to decommissioned services.
• Wayback Machine freshness: Monitor web.archive.org for leaked credentials or internal URLs in archived snapshots.
• GitHub dorking: Monitor GitHub search for org:yourcompany password, filename:.env org:yourcompany; use GitGuardian / TruffleHog.
• Pastebin monitoring: Use psbdmp.ws API or PasteHunter to detect leaked credentials or internal docs.

Social / Human Recon Indicators

• LinkedIn scraping patterns: Spike in profile views from unknown accounts; bulk profile data requests.
• Twitter / X mention anomalies: New accounts mentioning your brand keywords; sentiment shift.
• Job boards: Monitor your company's job posts for tech stack disclosure (informs attackers about your stack).
• Employee blog oversharing: Internal tools / project names disclosed in tech blogs; alert via Google Alerts.

Decoy / Honeypot Detection

• Canary tokens: Embed unique tokens (Thinkst Canary) in documents, DNS records, AWS API keys; alert on token activation.
• Honeypot subdomains: Deploy fake vpn-internal.yourdomain.com, git.yourdomain.com — any DNS resolution indicates enumeration.
• Fake breach data: Plant fake user admin_honeypot with known password in forums; alert on usage.
• Honeydocs: Track unique honeytokens in documents; alert when found in unexpected location.

SIEM Detection Rules

• Splunk SPL: index=dns query="*.yourdomain.com" | stats count by src_ip | where count > 100
• Sigma rule: sigma/rules/recon/subdomain_enum.yml — detects subfinder/amass patterns.
• AWS CloudTrail: Alert on Describe* API calls from unrecognized ARNs.
• GitHub: Audit log monitoring for repo.*.clone from new IPs.

Defense Evasion Techniques

Stealth Reconnaissance

• Passive over active: Prefer crt.sh (Certificate Transparency logs) over nmap -sS; no packets hit target.
• Rate limiting: Cap Shodan / Censys queries to legitimate research patterns; avoid bulk export API.
• Distributed source IPs: Use residential proxies for active recon; rotate to avoid WAF rate limiting.
• Off-peak timing: Schedule active scans during target's off-hours; blend with maintenance traffic.
• Source port spoofing: Use nmap --source-port 53 to look like DNS; --source-port 80 to look like HTTP.

Search Engine Dorking Stealth

• Distributed queries: Use multiple search engines (Google, Bing, DuckDuckGo, Brave Search) to distribute query load.
• Search operators in payloads: Avoid obvious inurl:admin patterns; use natural language queries that yield same results.
• Custom search engines: Yandex, Baidu, Mojeek often index different content than Google; less likely to be alerted.
• Search Console manipulation: Use Google's site: operator via custom scripts rather than browser — evades Google's anti-bot.
• Cached content access: Use cache: operator or web.archive.org to view content without hitting target.

Social Engineering Recon Stealth

• LinkedIn via proxy: Use LinkedIn Sales Navigator via legitimate subscription; avoid scraping patterns.
• Twitter/X API abuse: Use Twitter API for bulk mention lookups rather than browser scraping.
• Browser fingerprint variation: Rotate User-Agent, viewport, language to evade anti-bot (Cloudflare, PerimeterX).
• Multiple accounts: Distribute recon across multiple social media accounts to avoid rate limits and pattern detection.
• Burner accounts: Use single-use accounts for sensitive recon (no history to correlate).

Dark Web Monitoring Evasion

• Tor for dark web research: Use Tor for pastebin / forum access; rotate circuits per request.
• VPN chain: Tor + VPN combination for maximum anonymity during sensitive searches.
• Forum burners: Use unique credentials for each dark web forum; assume breach inevitable.
• Cryptocurrency for paid access: Use Monero (private) over Bitcoin for forum donations / paid access.

Code Repository Recon Stealth

• GitHub API over search: Use api.github.com/search/code with authenticated token rather than github.com/search (rate limits, less suspicious).
• Mirror repositories: Clone repos to local before searching; avoid git grep patterns across many repos.
• Fork before analyze: Fork target repo privately before scanning for secrets (don't reveal interest).
• TruffleHog locally: Run secret scanners locally rather than uploading to third-party scanning services.

Email / User Enumeration Stealth

• SMTP VRFY avoidance: Avoid VRFY command (logged); use RCPT TO responses instead.
• Microsoft 365 enumeration: Use GetCredentialType API endpoint (no log) over AutoDiscover (logged).
• Gmail enumeration: Use Gmail API rather than SMTP RCPT TO (rate-limited but less suspicious).
• OAuth consentGrant pattern: Use legitimate OAuth consent flow to enumerate user existence without SMTP.

Cloud Reconnaissance Stealth

• AWS S3 enumeration: Use ListObjectsV2 with valid credentials (no Anonymous flag); less suspicious than anonymous bucket checks.
• Azure Blob enumeration: Use Azure Storage Explorer with legitimate SAS tokens over anonymous GET.
• GCP Bucket enumeration: Use authenticated API calls rather than anonymous storage.googleapis.com GETs.
• Container registry recon: Pull images individually with delays rather than bulk skopeo sync.

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Hacker Laws

• First Principles Thinking: The essence of OSINT is information retrieval and correlation. Understanding search engine indexing principles, DNS query mechanisms, and Certificate Transparency protocols is necessary to design efficient collection strategies, rather than blindly stacking tools.
• Divergent Thinking First: Verify each intelligence target with at least 3 sources — search engines, certificate logs, DNS brute force, social media crawling. A single source inevitably has blind spots.
• Trust but Verify: OSINT data may be outdated, forged, or incomplete. WHOIS may be shielded by privacy protection, breach data may contain false information, social media accounts may be impersonated. All intelligence requires cross-verification.
• Obscurity Is Not Security: Information that targets think "nobody will find" is often the most dangerous. Public GitHub repositories, unprotected DNS records, and social media oversharing are all overlooked attack surfaces.

Learning Resources

• Supplementary files for this skill: payloads.md, test-cases.md
• Related skills: skills/recon-osint/SKILL.md, skills/social-engineering/SKILL.md, skills/social-intelligence/SKILL.md, skills/deep-research/SKILL.md, skills/password-attack/SKILL.md
• Tool memory files: osint/learning/OSINT_TOOLS_GUIDE.md, memory/maltego.md, memory/recon-ng.md
• External resources:
  • OSINT Framework: https://osintframework.com
  • TRACE Labs: https://tracelabs.org
  • IntelTechniques: https://inteltechniques.com
• Core system files: SOUL.md, TOOLS.md