Skip to content
Go back

OSINT Capture-The-Flag Cheatsheet

A practical cheat sheet for fast OSINT investigations during HTB, CTFs, TryHackMe and digital footprint challenges.


0. ESSENTIAL OSINT TOOLS

Web & Infrastructure

File & Image Metadata

Geolocation / Image Analysis

Archived Data / Web History

IP/Domain Intel


1. BASICS: IDENTIFIERS TO COLLECT

Collect:


2. USERNAME ENUMERATION

Sherlock


sherlock username

Maigret


maigret username

WhatsMyName

Cross-platform account detection.


3. EMAIL INTELLIGENCE

Social binding


holehe [[email protected]](mailto:[email protected])

Breach checks

Domain associations


theHarvester -d domain.com -b all

4. DOMAIN & SUBDOMAIN ENUMERATION

Subfinder


subfinder -d target.com -silent

Amass


amass enum -d target.com

CRT.sh

https://crt.sh/?q=target.com

Alive hosts


subfinder -d target.com | httpx -silent

5. IP & HOST INTEL

Shodan


[https://www.shodan.io/host/IP](https://www.shodan.io/host/IP)

Censys


[https://search.censys.io/hosts/IP](https://search.censys.io/hosts/IP)

VirusTotal

Check:


6. IMAGE / GEOLOCATION OSINT

Metadata extraction


exiftool image.jpg

GEOINT techniques


7. SOCIAL MEDIA OSINT

Twitter/X


from:user since:2023

Instagram

Check tagged accounts and EXIF of older posts.

Reddit

Pivot on post history + username reuse.


8. OSINT VIA PUBLIC FILES

Strings extraction


strings file.jpg

Extract embedded data


binwalk -e file.webp

Stego hints


9. ARCHIVE & HISTORICAL DATA

Wayback Machine


web.archive.org/web/*/target.com

Archive.today

Use for blocked pages.

CommonCrawl

Check past snapshots.


10. PHONE NUMBER / COUNTRY INTEL

Carrier & country lookup


[https://numverify.com/](https://numverify.com/)

OSINT pivot


11. WIFI / MAC / BLE OSINT

MAC vendor lookup


[https://maclookup.app/](https://maclookup.app/)

WiGLE

Locate BSSID / SSID on WiGLE.net.


12. DOCUMENT METADATA

PDF


exiftool file.pdf
pdfinfo file.pdf

Office docs


unzip file.docx -d out/
strings out/docProps/*

13. HASH / FILE OSINT

Hash file


sha256sum file
md5sum file

VirusTotal lookup

Get behavior, relations and samples.


14. GITHUB & PASTE OSINT


[https://github.com/search?q=username&type=code](https://github.com/search?q=username&type=code)

Paste sites


15. ADVANCED SHODAN FILTERS (INTEGRATED)

Shodan becomes extremely effective with combined filters.

By IP/range


net:1.1.1.0/24
ip:8.8.8.8

By port


port:22
port:443
port:8080
port:2375   # Docker
port:9200   # Elasticsearch

By service


product:Apache
product:"OpenSSH"
product:"Microsoft IIS"

By version


product:Apache version:2.4.49
product:"OpenSSH" version:7.2

By HTML content


html:"Index of /"
http.html:"password"
http.title:"login"

By country / city


country:ES
city:"Madrid"

By organization or ASN


org:"Google"
asn:13335

Vulnerability hunting examples

Log4Shell


product:Java "log4j"

Jenkins unauth


http.title:"Dashboard [Jenkins]"

MongoDB exposed


port:27017 "MongoDB Server"

SSL certificate filters


ssl:"domain.com"
ssl.cert.subject.cn:"*.example.com"
ssl.cert.issuer.cn:"Let's Encrypt"

Combined filters (very powerful)

Example: Hikvision cameras in Spain:


product:Hikvision port:80 country:ES

Example: Apache 2.4.49 worldwide:


product:Apache version:2.4.49

Example: Login panels in OVH France:


http.title:"admin" org:"OVH" country:FR

Shodan CLI


pip install shodan
shodan init <API_KEY>
shodan search "port:22 country:DE"
shodan host 8.8.8.8

Final Notes

This cheat sheet provides a complete OSINT workflow:

Useful for HTB OSINT challenges, CTFs, digital investigations and reconnaissance.



Share this post on:

Previous Post
BurpSuite Repeater/Intruder Power Tips
Next Post
Reverse Shells & Web Shells Cheatsheet