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Introduction:
Open Source Intelligence (OSINT) is no longer a niche skill for spy agencies; it’s a core competency for every penetration tester, SOC analyst, and forensic investigator. The post highlights a growing trend where professionals are pursuing structured OSINT validation—like the “Permis OSINT” (OSINT License) from France and the prestigious GOSI certification from SANS—to legally and effectively map attack surfaces, investigate threats, and comply with financial intelligence duties (LBCFT). This article dissects the tools, commands, and methodologies behind modern OSINT, giving you a hands-on roadmap from reconnaissance to reporting.
Learning Objectives:
- Master command-line OSINT techniques using legitimate open data sources (DNS, search engines, archives).
- Deploy automated reconnaissance frameworks to map an organization’s external attack surface.
- Apply OSINT findings to real-world scenarios: penetration testing, fraud investigation, and compliance checks.
You Should Know:
- The “OSINT License” Mindset – Ethical Reconnaissance Foundations
The “Permis OSINT” referenced in the post isn’t a legal permit but a training badge that enforces ethical boundaries. Before running any command, understand that OSINT uses publicly available data—no hacking, no brute force, no social engineering. This step‑by‑step guide sets up your environment and first passive queries.
Step 1: Isolate your OSINT workstation
Use a dedicated VM (Linux recommended) to avoid cross‑contamination with personal browsing.
Ubuntu/Debian – install core OSINT tools sudo apt update && sudo apt install -y curl wget dnsutils whois nmap theharvester recon-ng
Step 2: Passive DNS enumeration
Gather subdomains without touching the target servers using `dnsrecon` in passive mode or `curl` with public APIs.
Passive subdomain discovery via certificate transparency curl -s "https://crt.sh/?q=%.example.com&output=json" | jq -r '.[].name_value' | sort -u
Step 3: Historical WHOIS and DNS records
Use `whois` and third‑party archives like `securitytrails` (free tier).
whois example.com | grep -i "creation|registrar|name server"
Windows (PowerShell)
Get-Content .\domains.txt | ForEach-Object { Resolve-DnsName $_ -Type A }
Step 4: Directory and file discovery via search engines
Leverage Google dorks (manual) or `pagodo` (automated).
Search for exposed .env or .git files on a domain python3 pagodo.py -d example.com -g dorks.txt -e 2.0
What this does: These commands map an organization’s digital footprint—subdomains, IP history, forgotten staging servers—without sending a single packet to the target. Use results to build an attack surface inventory before any active scanning.
2. Automating OSINT with Recon‑ng and TheHarvester
Recon‑ng is a full‑featured reconnaissance framework with modules for every data source. TheHarvester extracts emails, subdomains, and hosts from search engines, PGP key servers, and LinkedIn.
Step 1: Launch Recon‑ng and set workspace
recon-ng [recon-ng]> workspace create target_osint [recon-ng]> marketplace install all
Step 2: Passive domain reconnaissance
[recon-ng]> modules load recon/domains-hosts/brute_hosts [recon-ng]> options set SOURCE example.com [recon-ng]> run
Step 3: Email and employee discovery
Use LinkedIn via `theHarvester` (respect rate limits).
theHarvester -d example.com -b linkedin -l 500 -f linkedin_report
Extract potential usernames from collected emails
cat linkedin_report.html | grep -oP '[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+.[a-zA-Z]{2,}' >> emails.txt
Step 4: Combine results into an attack surface graph
Create a simple CSV of findings
echo "subdomain,ip,source" >> inventory.csv
for sub in $(cat subdomains.txt); do host $sub | grep "has address" | awk '{print $1","$4",dns}'; done >> inventory.csv
Windows equivalent (PowerShell with `Invoke-WebRequest`):
Basic search engine OSINT
$query = "site:example.com filetype:pdf confidential"
$url = "https://www.google.com/search?q=$query"
Invoke-WebRequest -Uri $url -Headers @{"User-Agent"="Mozilla/5.0"} | Select-Object -ExpandProperty Content
Best practice: Always add delays (sleep 5-10) and rotate user‑agents to avoid temporary IP blocks. Use proxies if conducting large‑scale research.
- Image and Metadata OSINT – Extracting Hidden Clues
A single photo uploaded to a company blog can reveal GPS coordinates, camera models, or usernames. The post’s mention of “forensics” ties directly to metadata extraction.
Step 1: Extract EXIF data using `exiftool`
Install exiftool sudo apt install exiftool Extract all metadata from an image exiftool -a -u -g1 suspect_image.jpg
Step 2: Reverse image search via command line
Use `google-images-download` (Python) or `tineye` API.
Example using `tineye` (requires API key) curl -X POST "https://api.tineye.com/rest/search/" -F "[email protected]" -H "Authorization: Bearer YOUR_KEY"
Step 3: Geolocate using `exiftool` + `geocode`
If GPS present:
exiftool -GPSLatitude -GPSLongitude image.jpg Convert to decimal and paste into Google Maps
Step 4: Check for embedded thumbnails or hidden files
Scan for alternate data streams (Windows) dir /r suspicious_file.jpg Linux – binwalk to detect embedded files binwalk -e suspect_image.jpg
Why it matters: In incident response, a leaked photo with metadata can pinpoint the exact cubicle where a document was photographed. For penetration testing, metadata from corporate social media posts often reveals internal drive paths, software versions, and employee names.
- API Security and OSINT – Finding Leaked Keys
Every OSINT pro should check public code repositories for accidentally committed API keys, tokens, or credentials. The post’s “IT & AI engineering” context makes API reconnaissance critical.
Step 1: Search GitHub using `truffleHog`
Install truffleHog pip install trufflehog Scan a specific organization’s public repos (no clone needed) trufflehog github --org=example_org --only-verified
Step 2: Search Git commits for high‑entropy strings
Use `gitleaks` on a cloned repo git clone https://github.com/example_org/repo.git gitleaks detect --source=./repo --verbose
Step 3: Validate discovered API keys
Treat any found key as potentially valid. Test it discreetly (DO NOT call production endpoints aggressively).
Simple check for a Google Maps API key curl "https://maps.googleapis.com/maps/api/geocode/json?address=Paris&key=AIza_LEAKED_KEY"
Step 4: Automate with Shodan and Censys for exposed secrets
Search for default credentials in cloud storage shodan search "mongodb server info" --fields ip_str,port censys search "services.http.response.html_title:Jupyter" --index certificates
Mitigation for defenders: Regularly scan your own GitHub orgs. Set up secret scanning in GitHub Advanced Security. Rotate all leaked keys immediately—do not merely revoke them.
- Cloud Hardening & OSINT – Mapped Attack Surface
Attackers use OSINT to find cloud buckets, misconfigured databases, and open Kubernetes dashboards. This section bridges OSINT with cloud misconfiguration detection.
Step 1: Find public S3 buckets using `bucket_finder` or simple wordlist
Common bucket naming patterns
for name in $(cat bucket_words.txt); do
curl -s "http://${name}.s3.amazonaws.com" -I | head -1 | grep "200 OK" && echo "Bucket exists: $name"
done
Step 2: Enumerate Azure Blob containers
Using `microburst` (Azure OSINT toolkit) python3 microburst.py -d example.com -o azure_buckets.txt
Step 3: Check for open .git/.svn exposure on web servers
Simple one‑liner to test a target list for url in $(cat urls.txt); do curl -s -k "$url/.git/config" | grep -q "repositoryformatversion" && echo "$url EXPOSED"; done
Step 4: Framework for responsible disclosure
Once you identify misconfigurations:
- Document with screenshots and commands.
- Validate it’s not a honeypot or test environment.
- Contact `[email protected]` with a clear impact description.
- Never download or modify data.
Real‑world impact: The average cloud breach costs $4.5M – most start with an exposed S3 bucket found via OSINT. Tools like `CloudFox` or `ScoutSuite` can later be used for authenticated hardening checks.
6. Linux/Windows Commands for Live OSINT Investigations
When you need to pivot from passive to active (with permission), these commands are your daily drivers.
Linux – Network and DNS evidence collection:
Passive network monitoring sudo tcpdump -i eth0 -s 1500 -c 1000 -w capture.pcap Extract all unique domain names from a packet capture tshark -r capture.pcap -T fields -e dns.qry.name | sort -u Live whois + ASN mapping whois $(dig +short example.com | head -1) | grep "origin"
Windows – OSINT for incident handlers:
Extract all unique remote IPs from firewall logs (example log format)
Get-Content C:\Windows\Logs\Firewall\pfirewall.log | Select-String "DROP" | ForEach-Object { ($_ -split " ")[bash] } | Sort-Object -Unique
Retrieve certificate transparency logs for a domain via PowerShell
Invoke-RestMethod -Uri "https://crt.sh/?q=%25.example.com&output=json" | ConvertFrom-Json | Select-Object -ExpandProperty name_value
Unified reporting command:
Generate a markdown report of all findings echo " OSINT Report for $(date)" > report.md echo " Subdomains" >> report.md cat subdomains.txt >> report.md echo " Emails" >> report.md cat emails.txt >> report.md
What Undercode Say:
- OSINT is a force multiplier – A single email address exposed in a GitHub commit can lead to a complete corporate account takeover via password reuse.
- Automate but validate – Tools like Recon-ng and TheHarvester save hours, but manual verification prevents false positives from poisoning your intel.
- The “Permis OSINT” reflects a cultural shift – European professionals recognize OSINT as a core skill for LBCFT (anti‑money laundering) and GDPR compliance; expect similar certifications globally.
- Combine OSINT with active scanning – Mapping the surface first reduces noise and legal risk during authorised pentests.
- Defenders must think like OSINT analysts – Regularly Google your own domain, check Shodan for exposed services, and monitor certificate logs for unauthorized subdomains.
- AI enhances pattern recognition – Tools like `maltego` with AI transforms can predict attack paths from scattered OSINT data.
- Command‑line OSINT is faster and repeatable – Script your reconnaissance to stay ahead of threat actors who already have playbooks.
- Respect robots.txt and terms of service – The difference between OSINT and illegal access often comes down to rate limiting and authentication.
- SANS GOSI remains the gold standard – But free courses (like Permis OSINT) lower the barrier for junior analysts.
- Every breach starts with reconnaissance – By learning OSINT, you learn how attackers think before they strike.
Prediction:
By 2027, OSINT will become a mandatory module in all SOC analyst and penetration testing certifications (CEH, OSCP, CISSP). As generative AI automates data aggregation, the value will shift to interpretation—connecting a leaked credential to a cloud bucket to a specific employee’s LinkedIn profile. France’s “Permis OSINT” is a precursor to national OSINT governance frameworks across the EU, potentially requiring formal licensing for commercial investigators. Organizations that embed OSINT into their purple teaming exercises will cut their mean time to detection by over 60%, while those ignoring it will continue to bleed data from public sources they never knew existed.
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Reported By: Regis Deldicque – Hackers Feeds
Extra Hub: Undercode MoN
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