OSINT › Module 4 › Lesson 3
theHarvester on a Domain YOU Own
theHarvester -d YOURDOMAIN only — Skip if no domain.
Visual · theharvester_owned_domain
github.com/laramies/theHarvester -d YOURDOMAIN.
Opening
Harvester is a vacuum. If the domain is not yours, you are vacuuming someone else’s porch.
theHarvester (github.com/laramies/theHarvester) queries public sources for emails and hosts tied to a domain. That is legitimate on a domain you registered and are defending. It is not legitimate on your school, your employer (unless they wrote you a pentest RoE — not this course), or a random brand. If DOMAIN=none, skip the tool entirely. Original Cyberlium. GATE 192.168.0.1. Install from official GitHub or documented package. Never -d classmate.com. Never nmap the results. Next: Lab — Check YOUR Email Footprint.
1. Install official, then gate -d on YOUR DOMAIN
git clone https://github.com/laramies/theHarvester or follow that repo’s install docs. Before any run, compare -d to scope.env DOMAIN. Mismatch means stop.
example.com may appear in docs; do not harvester-scan living companies “because the README did.” ; do not -d the home router hostname.
Command guide
Install official, then gate -d on YOUR DOMAIN
═══ INSTALL ═══
Linux (Debian/Ubuntu):
Command — copy this
pipx install theHarvester
macOS:
Command — copy this
pipx install theHarvester
Windows:
Command — copy this
pip install theHarvester
═══ LINUX / macOS ═══
Gather emails, subdomains, and hosts from public sources
Command — copy this
theHarvester -d example.com -b google theHarvester -d example.com -b duckduckgo -l 200 theHarvester -d example.com -b all -l 500
═══ WINDOWS ═══
Command — copy this
theHarvester -d example.com -b google theHarvester -d example.com -b duckduckgo -l 200
2. Run -d YOURDOMAIN or write skip; save privately
If you own the domain, a small theHarvester run (few sources, short) into a 600 file is the lab. Read emails that are yours; unexpected addresses on YOUR domain are still YOUR problem to fix (aliases, old seats).
If an email appears that is not you but is on your domain (a friend you gave a mailbox), that is still your domain admin problem — you do not then pivot to Sherlock that friend for this course. You fix mailboxes you administer.
3. Never-list: school, employer-without-RoE, LAN, dumps
theHarvester -d university.edu because you have a student email is still harvesting an institution you do not own. Out. nmap of discovered hosts: out. Buying dumps to enrich: out.
Lab next: HIBP official site for YOUR email plus a merged footprint file.
4. What you ship: theHarvester only on YOUR domain, or a written skip
Official laramies/theHarvester. -d matches scope.env DOMAIN you own, or skip. No school harvest. DEMO GATE. Notes 600.
5. What you record before the next lesson
Date. DOMAIN or skip. theHarvester URL. NEVER school. File t12-m04-l03-theharvester.txt chmod 600.
6. Wrong vs right: strangers vs identifiers YOU own
Worked failure — same OSINT word, opposite target. Right never needs a classmate or a dump site.
Wrong
theHarvester -d school.edu. nmap the host list. Hunter.io a local business.
Right
Own domain or skip. Next: Lab — Check YOUR Email Footprint.
Mission: harvest only if you own the domain
1) / STOP if router. 2) If DOMAIN is yours, theHarvester -d YOURDOMAIN (official tool). 3) If none, write skip. Never school/employer-without-RoE. Never nmap results.
Stuck? Ask Cyberlium AI Mentor
Ask Mentor how to read a skip as a valid lab — not how to pick a “practice company.”
Knowledge Check
APPLY: You have a school.edu mailbox but do not own the domain. theHarvester?
Multiple choice
Knowledge Check
APPLY: True or False: Official theHarvester is https://github.com/laramies/theHarvester.
True or False
Knowledge Check
APPLY: curl http://192.168.0.1/ is Router Admin. You theHarvester it?
Multiple choice