OSINT › Module 5 › Lesson 3
security.txt robots.txt and humans.txt
RFC 9116 security.txt, robots.txt, humans.txt — example.com literacy + local file. DEMO GATE. 8804.
Visual · securitytxt_robots_humans
curl https://example.com/.well-known/security.txt.
Opening
Some sites publish a security contact on purpose. Read that file; do not invent a backdoor.
security.txt (RFC 9116, securitytxt.org) is a well-known path where a site owner can publish how to report vulnerabilities. robots.txt tells crawlers what not to harvest. humans.txt is an informal credits file. You may curl https://example.com/.well-known/security.txt as literacy. If you own a site, curl yours. If you own none, write a local security.txt in cyberlium-lab as practice text — not as a fake.gov. Original Cyberlium. GATE 192.168.0.1 still heading 1. Never curl a classmate site’s security.txt to “collect contacts.” Never nmap. Next: Lab — Domain File for YOUR Name.
1. RFC 9116: a published contact, not a hunt
https://securitytxt.org/ explains the format. Path: /.well-known/security.txt (and sometimes /security.txt). curl example.com as literacy. For YOUR site, substitute. Missing file is a finding for a defender you (if you own the site).
with curl on 192.168.0.1. Do not fetch security.txt from a home gateway and call it RFC 9116 practice.
Command guide
RFC 9116: a published contact, not a hunt
═══ INSTALL ═══
Linux (Debian/Ubuntu):
Command — copy this
sudo apt install curl
macOS: Built-in
Windows: Built-in (PowerShell: Invoke-WebRequest)
═══ LINUX / macOS ═══
Check security.txt (RFC 9116)
Command — copy this
curl -sS https://example.com/.well-known/security.txt curl -sS https://google.com/.well-known/security.txt
Check robots.txt
Command — copy this
curl -sS https://example.com/robots.txt
═══ WINDOWS ═══
Optional command
PowerShell
Command — copy this
Invoke-WebRequest -Uri 'https://example.com/.well-known/security.txt' | Select-Object -ExpandProperty Content Invoke-WebRequest -Uri 'https://example.com/robots.txt' | Select-Object -ExpandProperty Content
2. robots.txt and humans.txt: crawler policy and credits
curl -sS https://example.com/robots.txt | head. Disallow lines are requests to crawlers, not a treasure map you must fetch. humans.txt if present is credits. On YOUR site, read yours. On other people’s sites, do not scrape Disallow paths as an attack list.
If you have no site, skip remote robots and still write local samples under cyberlium-lab.
3. Local security.txt in cyberlium-lab if you have no domain
RFC 9116 fields you can practice locally: Contact, Expires, Preferred-Languages. Write a file that lists YOUR email from scope — chmod 600. That is not impersonating example.com.
Lab next: one domain file merging WHOIS, DNS, and well-known notes for YOUR name.
4. What you ship: example.com well-known curls, local security.txt, RFC 9116 URL
curl example.com/.well-known/security.txt and robots.txt. Local $HOME/cyberlium-lab/security.txt chmod 600. YOUR site if owned. DEMO GATE. No classmate well-known harvest.
5. What you record before the next lesson
Date. RFC 9116 / securitytxt.org. example.com curls. local security.txt. File t12-m05-l03-securitytxt.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
Scrape robots Disallow on a bank as a target list. Fetch a classmate security.txt to email them. Bind a fake.gov security.txt to 0.0.0.0.
Right
example.com literacy + local file + YOUR site if any. Next: Lab — Domain File for YOUR Name.
Mission: read well-known files you are allowed to read
1) / STOP if router. 2) curl example.com/.well-known/security.txt and robots.txt. 3) Write local security.txt in cyberlium-lab chmod 600. 4) YOUR site if owned. Never classmate well-known files as collection.
Stuck? Ask Cyberlium AI Mentor
Ask Mentor what RFC 9116 Contact is for — not how to spam every security.txt you can find.
Knowledge Check
APPLY: You own no domain. security.txt practice?
Multiple choice
Knowledge Check
APPLY: True or False: robots.txt Disallow is a loot map you must fetch.
True or False
Knowledge Check
APPLY: Official security.txt project URL named here?
Multiple choice