performing-external-network-penetration-test

name	performing-external-network-penetration-test
description	Conduct a comprehensive external network penetration test to identify vulnerabilities in internet-facing infrastructure using PTES methodology, reconnaissance, scanning, exploitation, and reporting.
domain	cybersecurity
subdomain	penetration-testing
tags	["external-pentest","network-security","PTES","OSSTMM","Nmap","Metasploit","vulnerability-assessment","reconnaissance","exploitation"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["ID.RA-01","ID.RA-06","GV.OV-02","DE.AE-07"]
mitre_attack	["T1595","T1190","T1059","T1078","T1592"]

Performing External Network Penetration Test

Overview

An external network penetration test simulates a real-world attacker targeting an organization's internet-facing assets such as firewalls, web servers, mail servers, DNS servers, VPN gateways, and cloud endpoints. The objective is to identify exploitable vulnerabilities before malicious actors do, following frameworks like PTES (Penetration Testing Execution Standard), OSSTMM, and NIST SP 800-115.

When to Use

• When conducting security assessments that involve performing external network penetration test
• When following incident response procedures for related security events
• When performing scheduled security testing or auditing activities
• When validating security controls through hands-on testing

Prerequisites

• Written authorization (Rules of Engagement document signed by asset owner)
• Defined scope: IP ranges, domains, subdomains, and exclusions
• Testing environment: Kali Linux or Parrot OS with updated tools
• VPN/dedicated testing infrastructure to avoid IP blocks
• Coordination with SOC/NOC for timing windows

Phase 1 — Pre-Engagement and Scoping

Define Rules of Engagement

Scope:
  - Target IP ranges: 203.0.113.0/24, 198.51.100.0/24
  - Domains: *.target.com, *.target.io
  - Exclusions: 203.0.113.50 (production DB), *.staging.target.com
  - Testing window: Mon-Fri 22:00-06:00 UTC
  - Emergency contact: SOC Lead — [phone]
  - Authorization ID: PENTEST-2025-EXT-042

Legal Documentation Checklist

Document	Status	Owner
Master Service Agreement (MSA)	Signed	Legal
Statement of Work (SOW)	Signed	PM
Rules of Engagement (RoE)	Signed	CISO
Get-Out-of-Jail Letter	Signed	CTO
NDA	Signed	Legal
Insurance Certificate	Verified	Risk

Phase 2 — Reconnaissance (Information Gathering)

Passive Reconnaissance

# OSINT — Subdomain enumeration
subfinder -d target.com -o subdomains.txt
amass enum -passive -d target.com -o amass_subs.txt
cat subdomains.txt amass_subs.txt |  -u > all_subs.txt


dig target.com ANY +noall +answer
dig target.com MX +short
dig target.com NS +short
dig target.com TXT +short


whois target.com
whois -h whois.radb.net -- 


curl -s  | jq  |  -u







shodan search  --fields ip_str,port,product
shodan host 203.0.113.10


theHarvester -d target.com -b all -l 500 -f theharvester_results


trufflehog github --org=targetcorp --concurrency=5
gitleaks detect --=https://github.com/targetcorp/repo