A penetration test is an authorized simulated cyberattack on a system, network, or application to identify security vulnerabilities. Penetration testers (pen testers) use the same tools and techniques as real attackers, but legally and ethically, to find weaknesses before malicious actors exploit them.
The first phase collects as much intelligence as possible about the target. Passive reconnaissance gathers public information without alerting the target: WHOIS lookups, DNS records, social media profiles, and job postings. Active reconnaissance involves direct interaction—port scanning, network mapping, and service enumeration.
nmap -sV -sC -A 192.168.1.0/24Determines which services are running, their versions, and potential vulnerabilities. Nessus and OpenVAS perform automated vulnerability scanning. Burp Suite proxies web traffic.
Raw scanning data transforms into actionable intelligence. The pen tester prioritizes findings by severity, exploitability, and business impact.
The pen tester attempts to exploit identified flaws to gain unauthorized access, escalate privileges, or move laterally through the network.
use exploit/windows/smb/ms17_010_eternalblue
set RHOSTS 192.168.1.100
runThe final phase translates technical findings into business context. The pen test report documents every vulnerability, how it was discovered, the impact, and remediation steps.
Penetration testing without authorization is illegal. Always obtain written permission before testing. The rules of engagement (RoE) document must specify scope, systems to test, attack restrictions, and emergency shutdown procedures.