Offensive Security: Penetration Testing Best Practices

Penetration testing, or pentesting, helps organizations discover weaknesses before real attackers do. Following best practices keeps tests useful and safe. A solid engagement starts with clear goals, defined scope, and written authorization.

Plan and scope A good plan reduces risk and guides the work. Before testing begins, confirm who has approval, what systems are in scope, and what methods are allowed. Agree on time limits, data handling rules, and how findings will be shared.

• Define assets to test (servers, apps, networks) and exclude anything off-limits.
• Set depth and duration of the test to avoid overloading systems.
• Establish reporting expectations and data protection rules.

Methodology Use a structured approach to find real risks. Typical steps include reconnaissance, discovery, vulnerability analysis, controlled exploitation where permitted, post-exploitation, and cleanup. Keep notes, document evidence, and respect the limits agreed in the plan.

• Reconnaissance and mapping to understand the target surface.
• Identify weaknesses aligned with risk, not every vulnerability.
• Validate findings with evidence such as screenshots or logs.
• If allowed, demonstrate impact with safe, non-destructive tests.
• Document remediation steps and priorities for fixes.

Evidence and reporting Clear reports help teams fix issues quickly. Provide evidence, risk ratings, impact, likelihood, and concrete fixes. Include a remediation plan, timelines, and suggested mitigations.

Ethics and safety Always follow a code of conduct: permission in writing, data protection, and responsible disclosure. Work in a controlled environment when possible and minimize any disruption to users.

Tools and environments Prefer isolated test environments when possible. Use reputable tools, keep them updated, and log every action. Capture before-and-after results to show improvements.

Continuous improvement Treat every engagement as a learning opportunity. Share lessons within the team, update playbooks, and plan targeted retests after fixes.

Example for web applications Start with non-authenticated discovery, map endpoints, test input handling, and session management. Focus on high-risk areas like authentication, authorization, and data exposure, then verify fixes with follow-up tests.

Key Takeaways

• Plan the scope, authorization, and data handling before testing.
• Use a structured methodology and clear evidence in reports.
• Maintain ethics, safety, and proper disclosure throughout the process.