How To Prepare For A Penetration Test

Penetration testing (ethical hacking) is a simulated cyberattack on your IT systems designed to uncover vulnerabilities before malicious hackers can exploit them. But the success of any penetration test heavily depends on one factor; how well you prepare for it.

Without proper planning, a penetration test can fail to deliver meaningful insights, disrupt operations, or even introduce unnecessary risks. In this post, we’ll outline what your organisation needs to prepare before undergoing a penetration test or security audit.

How Many Documents Do You Need to Prepare Before a Penetration Test?

Before your penetration test even begins, there are a few key documents that need to be completed. These ensure both you and your testing provider are aligned on scope, responsibilities, and legal requirements. Typically, you’ll encounter three main documents:

1. Scoping Form

This is the starting point of the engagement. The scoping form captures the technical details of your project, such as the systems, applications, or networks in scope. Your penetration testing provider will use this information to determine the number of days required, the resources needed, and the overall cost.

2. Statement of Work (SoW)

Once the scope is agreed, the Statement of Work formalizes it. This document outlines exactly what will be tested, how it will be tested, and what you’ll receive at the end. It usually includes:

Deliverables (e.g., final report, executive summary)
Timescales and milestones
Methodology and tools to be used

Essentially, the SoW acts as the contract for the engagement.

3. Authorisation Form

This is the final sign-off before testing begins. It typically includes:

Customer points of contact
Legal clauses around confidentiality, liability, and data handling
Testing windows and any restrictions
Final details such as IP addresses, credentials, or other sensitive information

The most important element here is the formal authorisation to test, which protects both you and the provider legally. In some cases, this document is incorporated directly into the SoW. You should begin preparing for you penetration test once the statement of work has been signed.

How to Prepare for a Penetration Test: Benefits of Proper Preparation

When you prepare for a penetration test the right way, you gain:

Accurate identification of security weaknesses.
Improved vulnerability assessment and risk identification.
Valuable insights for compliance and audits.
Reduced risk of system outages.
Efficient coordination across departments.
Better post-test remediation planning.
Better work and reduced costs.

Organisations of all sizes and industries benefit from proper penetration test preparation, as it helps them strengthen their overall cybersecurity posture. Following best practice in preparation ensures you get maximum value from the test.

Step-by-Step Guide on How to Prepare for a Penetration Test

The preparation process involves several key steps. Let’s walk through the essential steps every organization must take to get ready. If you follow this process, you can break it down into six steps for a structured approach.

Define Clear Objectives for the Penetration Test

Start by defining your objectives:

What are we trying to achieve?
How large is the attack service?
Where is the most crucial data stored?
Are we testing a live system vs a staging environment?
Are third party stakeholders involved?

After answering these questions, it is crucial to determine what needs to be tested and why, as this will guide the entire process. Defining the scope is a crucial part of this step, ensuring that all relevant assets and boundaries are included. Clear goals should be determined at the outset, and it is crucial to identify priorities and success criteria to ensure the effectiveness of the assessment.

Understand the Scope of the Test

The scope defines which systems, networks, and applications will be tested. Scoping is essential for identifying the attack surface, ensuring that all relevant assets and entry points are considered. Include the key components of your environment, such as web applications, APIs, internal networks, cloud infrastructure, and, optionally, physical security, in the scope to ensure comprehensive coverage.

Clarifying scope prevents disruptions and ensures meaningful outcomes.

For example, do you want a web application penetration test which includes every page, parameter and user role on the web application? Or do you just need a specific new feature tested? Does this web application also connect to a database hosted somewhere other than the web server VIA an API? Should you include this in your scope to ensure it is also secured?. These are the types of conversations you should be having with your Penetration tester during scoping.

Choose the Right Type of Penetration Test

Each test type targets different risks:

External: Public-facing systems, often involving different user accounts to assess access controls and the potential impact of compromised credentials.
Internal: Simulates insider threats, where the tester or pen tester may use specific credentials and test accounts to mimic real employee access and evaluate internal security measures.
Wireless: Explores WiFi vulnerabilities, sometimes requiring test accounts to safely assess network segmentation and user account isolation.
Web Application / API: Testing the function of a web application or its APIs to check for the OWASP top 10
Social Engineering: Tests staff awareness, potentially targeting user accounts to demonstrate how attackers might exploit human factors.
Physical: Examines facility security, which may include attempts to access systems using stolen or guessed credentials.

Assemble an Internal Security Team

Designate team members to coordinate the test. Such as:

IT and network engineers
System administrators
Developers.
Executive sponsors

Assigning roles helps manage communication, documentation, and incident response. Ensure your team is prepared to respond quickly to any queries that may arise during the test. Having a human point of contact is essential for effective coordination. If something happens such as the firewall blocks the penetration tester or the website become unresponsive the penetration tester is going to want someone to discuss this with ASAP. Alternatively they might discover something they believe is a vulnerability but need further context to decide whether it is or not, sometimes features can look like vulnerabilities and its good to be able to get clarification from someone before they spend hours investigating it.

Select a Reputable Penetration Testing Provider

Many organizations focus on finding providers with relevant experience, certifications, and a proven track record in penetration testing. Because comprehensive testing requires specialized expertise, many organizations choose to work with external providers rather than relying solely on internal resources.

Look for vendors or consultant with:

Certifications like OSCP as a Minimum
Experience in your industry
Clear testing methodology
Positive client reviews

Most will provide a detailed Statement of Work (SoW) before proceeding.

Draft a Rules of Engagement Document

This agreement sets the test’s:

Scope
Timelines
Allowed tools and techniques
Emergency contacts
Data handling protocols
Access methods for the pen tester (such as VPN)
Staging Enviroments needed.
Whitelisting of penetration testers IPs.

Enabling the necessary access and communication channels is critical for a successful engagement. It protects both parties and ensures everyone is aligned.

Normally its a good idea to give your penetration tester access (IPs / users accounts / whitelisting) 5 days before there test is to begin so they can verify everything is working and accessible so they can hit the ground running on day one.

Review Regulatory and Compliance Requirements

Regulatory bodies may require specific tests or limit certain actions.

Ensure your test aligns with:

GDPR (data privacy)
PCI DSS (payment systems)
HIPAA (health data)
ISO/IEC 27001

Involve legal and compliance teams early on.

Inventory and Document All Systems

Provide testers with updated:

Network diagrams
System architecture
Application lists
Patch levels
Known vulnerabilities

Developing a comprehensive asset inventory is crucial for understanding the attack surface and defining the scope of the penetration test. Identifying all assets ensures that nothing is missed during the test and that the assessment covers every potential entry point. This ensures a comprehensive, efficient assessment. It also helps the tester have context if they discover a server or something which isn’t on your network diagram which you believed had been decommissioned butt it is in still there.

Create Backups and Enable Monitoring Tools

Before testing starts:

Back up all critical systems
Verify backup integrity
Enable logs and SIEM tools
Monitor system performance

Establish Communication Protocols

Honestly just give them a point of contact and phone number to call it doesn’t have to be that complicated someone who is technical and understands the system or application they are testing who they can speak to if they have issues / queries. It might be your product or website but a developer might be the better point of contact for this.

Designate point-of-contact personnel before the test begins.

Set up a communication tree
Define escalation procedures
Use secure messaging or ticketing systems
Decide how often status updates are shared

Clear communication reduces confusion and speeds up decision-making during the test. It is essential to communicate updates and incidents in a timely manner to ensure prompt response and effective coordination.

Notify Third Parties and Stakeholders

If your test involves systems or data that touch:

Cloud service providers
Third party software vendors
Partner systems

…you must notify them in advance. Some contracts prohibit or restrict penetration testing without consent.

Prepare a Safe Testing Environment

You have two options:

Production environment: Real-world results but higher risk, as testing in the production environment involves real user data, system availability, and accurately mirrors the live environment for security assessments
Staging/Test: Safer but may not reflect live behavior

If testing in the production environment:

Monitor systems closely
Ensure backups are ready
Test during off-peak hours

Train Staff on Awareness and Reporting

During the test, your staff may encounter:

Fake phishing emails
System anomalies
Unusual network activity

Train employees to report these incidents properly and don’t tip off testers unless part of the plan.

Anticipate Service Disruptions or False Positives

Penetration testing may cause:

Performance slowdowns
Alarms in your monitoring tools
Unexpected issues that were not anticipated during planning

Prepare for potential issues that could arise during the test, such as vulnerabilities or risks discovered that may impact your network or system.

Legal and Contractual Documentation

Before the test, ensure the following are in place:

NDA (Non-Disclosure Agreement)
Test Authorization Letter
Scope of Work (SoW)
Liability Clauses

These documents protect all parties and ensure compliance.

Plan for Post-Test Activities

Your preparation doesn’t stop when the test begins.

Get ready for:

Reviewing the final report and testing results
Prioritizing vulnerabilities, including detected vulnerabilities and identified vulnerabilities
Creating a remediation roadmap to address and ensure all identified vulnerabilities are addressed and remediation steps are complete
Assessing and evaluating the impact of detected vulnerabilities and how they were exploited during the test
Scheduling follow-up assessments to evaluate the effectiveness of fixes and assess ongoing risks
Updating policies and controls to integrate and ensure lessons learned are integrated into ongoing security processes
Identifying and addressing potential vulnerabilities discovered during the test

The real value of a penetration test lies in how you act on its findings. Focus on continuous improvement and integrate findings into your organization’s security strategy.

FAQs

How far in advance should I start preparing for a penetration test? Begin preparations at least 3–4 weeks before the scheduled pen test to align scope, approvals, documentation, and backups. This allows time to define the penetration testing process, clarify objectives, and ensure all processes are in place.

Do I need to inform all employees about the penetration test? Not always. In fact, unannounced pen tests may be part of the engagement, especially in social engineering. These simulate attacks without prior knowledge of security personnel, mirroring real-world scenarios. Inform only essential personnel.

What is included in the rules of engagement for penetration testing? It includes scope, authorized testing windows, attack methods, escalation contacts, and test objectives. The rules should also outline the penetration testing process, including the steps involved in conducting a pen test such as planning, vulnerability identification, exploitation, and reporting.

Can a penetration test break my system? While rare, some pen tests may cause performance issues. For example, a tester might perform fuzzing and scanning on your network which could cause latency issues (unlikely), if this happens just query it with them they can slow down the scans and work around problems your having. This is why backups, monitoring, and staging environments are critical. This is why its important to have a technical contact on standby to work with the penetration tester.

Do penetration testers need full access to our systems? It depends on the test type. The pen tester or tester may require different levels of access depending on the type of pen testing. White-box tests offer full access; black-box tests simulate external attacks with minimal access.

What should I do if the penetration test reveals critical vulnerabilities? Act immediately. Addressing vulnerabilities is crucial. The first step in the response process is to isolate the threat, inform stakeholders, and begin remediation according to your incident response plan.

Should I let the penetration test through my firewall?
Yes, in most cases, you should whitelist the penetration tester through your firewall. The purpose of a penetration test is to identify vulnerabilities in your systems, and allowing the tester through ensures their tools won’t be blocked prematurely. This way, the firewall itself can still be tested as part of the engagement, but the tester can also perform a more thorough assessment of the systems and applications. Whitelisting provides them with better visibility and ensures you get the most value from the test.

Conclusion

Understanding how to prepare for a penetration test is essential if you want actionable results without causing chaos. It’s not just about giving testers access—it’s about planning every detail:

Setting clear goals
Understanding the scope
Securing legal documentation
Protecting your systems
Coordinating your teams

A well-prepared penetration test leads to better security, stronger compliance, and a more resilient organization. Don’t treat it like a one-time event treat it like a cornerstone of your security posture.