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Penetration Test Fundamentals

Understanding the structure of a penetration test helps build a repeatable, professional process.
Each phase has its own purpose, tools, and mindset, and together they form a complete engagement.

Pre-Engagement Phase

This phase lays the foundation for a successful pentest.
Scope, objectives, and expectations are defined with the client.

Key deliverables include:

  • Rules of Engagement (RoE): Scope, testing boundaries, contact points, and emergency procedures
  • Legal Agreements: NDAs, contracts, and liability clauses
  • Communication Plan: Who to contact, when, and how (especially in case of critical findings)

Documentation is critical here. It protects both the tester and the client.

Information Gathering Phase

Also called reconnaissance. The goal is to collect data on the target.

  • Passive Recon: Publicly available information without touching the target (WHOIS, OSINT, DNS records)
  • Active Recon: Direct interaction with the target through scanning, service enumeration, and banner grabbing

This is the first intrusive step — every action must be documented carefully.

Vulnerability Assessment Phase

Analyzing recon data to identify potential weaknesses, such as:

  • Outdated software or services
  • Misconfigurations
  • Known vulnerabilities
  • Weak authentication mechanisms

This phase is creative. Small flaws can often be chained together into high-impact exploits.
Thinking this way helps justify remediation later — even “minor” issues can combine into something dangerous.

Exploitation Phase

Attempting to exploit the identified vulnerabilities.
The goal is to show real-world impact, not just theoretical risk.

Every step must be documented:

  • What was exploited
  • How it was exploited
  • What access was gained
  • Evidence that the RoE was respected

This phase proves the vulnerabilities are real and actionable.

Post-Exploitation Phase

Once initial access is gained, explore what an attacker could do next:

  • Privilege escalation
  • Data access and exfiltration testing
  • Persistence mechanisms
  • Network mapping and trust discovery

The goal is to understand the full scope of compromise, not just the entry point.

Lateral Movement Phase

Expanding access across the network by exploiting trust relationships.
Techniques include:

  • Credential harvesting
  • Pass-the-hash
  • Exploiting network protocols

Lateral movement shows how an attacker could pivot to sensitive systems beyond the initial breach.

Proof of Concept

Building reproducible examples of findings, including:

  • Scripts or tools used
  • Step-by-step instructions
  • Conditions required for exploitation

The goal is to help the client’s technical team understand, verify, and test fixes.

Post-Engagement Phase

Translating technical findings into actionable insights.
The report should include:

  • Executive summary for leadership
  • Technical details for IT/security teams
  • Screenshots, logs, and evidence
  • Risk ratings and remediation recommendations

A good report is clear, honest, and tailored to the audience.

Remediation Support & Retesting

After the report is delivered, support may continue during remediation:

  • Answering questions
  • Clarifying findings
  • Offering guidance on fixes

Once fixes are applied, a retest verifies vulnerabilities are resolved and no new issues were introduced.
This final step ensures the engagement leads to real security improvements.