5 steps to more effective penetration testing

Penetration testing, also known as ethical hacking, is a critical process for identifying security vulnerabilities before malicious hackers can exploit them. By simulating real-world attacks, organizations can strengthen their defenses, protect sensitive data, and ensure compliance with security regulations.

However, up to 1 in 3 companies don’t effectively implement penetration tests on a regular basis, with tight budgets often cited as the reasons why this crucial approach to security is overlooked. So, how can your organization ensure it makes the most of pen testing?

In this guide, we’ll outline five essential steps, discuss popular tools, best practices and challenges, and provide real-world examples of penetration testing in action to help you leverage this vital cybersecurity process.

5 Steps in Penetration Testing

Penetration testing follows a structured approach to systematically uncover security weaknesses. By progressing through these five essential steps, security professionals can simulate real-world attacks, identify vulnerabilities, and provide actionable insights to strengthen defenses.

1. Reconnaissance (Information Gathering)

The first step in effective penetration testing is reconnaissance, also known as information gathering, and we highly recommend that you begin by collecting as much data as possible about the target system, network, or application.

In general, ethical hackers will use passive and active reconnaissance techniques to gather information. Passive reconnaissance includes analyzing publicly available data, such as domain records, social media, and public repositories. Active reconnaissance involves directly interacting with the target system using techniques like network scanning and Domain Name System (DNS) enumeration to identify potential vulnerabilities.

2. Scanning

In this stage, penetration testers conduct a comprehensive scan of the target system or network to identify open ports, active services, and potential entry points for attacks. This process, known as vulnerability scanning, provides critical insights into where security weaknesses exist.

While many organizations rely on automated vulnerability scans without following up with penetration testing, this approach is insufficient. Knowing where vulnerabilities exist is not the same as understanding how attackers can exploit them. Without deeper analysis, businesses risk overlooking critical security gaps.

This stage allows external and internal penetration testers to map out all active services and ports where malicious activity is most likely to take place. Doing so helps to make the next few stages of the process more efficient and precise.

3. Vulnerability Assessment

The third step of penetration testing goes deeper into how open ports and active services can be exploited. At this stage, after collecting relevant data through reconnaissance and scanning, testers analyze the system for known security weaknesses. This involves cross-referencing findings against databases such as the Common Vulnerabilities and Exposures (CVE) list.

By determining which vulnerabilities pose the highest risk, penetration testers can prioritize them for further testing and exploitation attempts. During specific types of tests, such as those within black box penetration testing, assessors will have no prior knowledge of vulnerabilities or systems.

4. Exploitation

This phase is where penetration testers actively exploit identified vulnerabilities to gain unauthorized access, mimicking real-world cyberattacks. It is a critical step in understanding the true impact of security flaws, as it reveals how easily an attacker could infiltrate the system and what damage they could inflict.

Typical attacks include injecting code, running distributed denial of service (DDoS) attacks, setting up cross-site scripting, or brute-forcing password attempts. The attacks a tester uses will depend entirely on the vulnerabilities they’ve scanned and assessed in steps two and three.

Beyond initial access, testers examine how the system operates as a whole, mapping communication channels, tracing network traffic, and identifying connections between different systems. Post-exploitation efforts focus on maintaining persistence, escalating privileges, and determining the extent to which an attacker could move laterally across the network. The goal is to assess how much sensitive data is at risk, whether an attacker could exfiltrate information, and how long an undetected presence could be sustained.

5. Reporting

The final stage of penetration testing is reporting and remediation, where testers document their findings and provide actionable recommendations to strengthen security. This step ensures that organizations not only understand their vulnerabilities but also have a clear roadmap to address them effectively.

A comprehensive penetration testing report typically includes:

• Identified vulnerabilities, ranked by severity and risk level
• Step-by-step attack scenarios, detailing how each weakness was exploited
• Potential impact analysis, highlighting what data or assets were at risk
• Clear remediation guidance, offering best practices for mitigation

However, fixing vulnerabilities is only part of the process. Once remediation steps have been implemented, testers conduct a follow-up assessment, including rescanning and revalidation, to ensure that the issues have been effectively resolved and no new security gaps have emerged.

By translating technical findings into clear, practical security improvements, penetration testers help organizations not only patch current weaknesses but also strengthen their overall security posture against future threats.

Popular Penetration Testing Tools

Some of the most commonly used penetration testing tools include:

• Wireshark: An open-source network protocol analyzer that captures and inspects packet data to identify potential network issues.
• Hashcat: A fast and versatile password-cracking tool that supports various hashing algorithms, aiding in testing password strength.
• John the Ripper: A flexible password cracker that detects weak passwords across different operating systems and applications.
• Hydra: A parallelized login cracker supporting numerous protocols, used to test the strength of passwords and authentication mechanisms.

Of course, the tools and penetration testing methodologies used by testers will vary from case to case, and client to client. Some will be more beneficial during external penetration tests as opposed to internal assessments, for instance.

Penetration Testing Best Practices and Common Challenges

There are a few common challenges that face penetration testers regardless of the practices used. These include:

• Resource availability and scheduling problems: It’s always important for clients to work closely with testers so that there’s a clear plan in place, allowing for max flexibility for testing and remediation.
• Inconsistency: Disorganized penetration testing can lead to confusing results and advice that simply doesn’t work in practice – testers should therefore consider working to frameworks such as those set by the Open Worldwide Application Security Project (OWASP).
• Communication breakdown: It’s vital for pen testers to speak openly and plainly with clients so that they understand what’s happening at each stage of the process – otherwise, they might struggle to understand how to put advice into practice.

At VikingCloud, we recommend adhering to the following best practices (among others):

• Agree on a clear scope and budget: Professional, reliable testers will always be open with clients on costs and timescales. Therefore, it’s important for company operators to discuss which systems and infrastructure areas are the biggest priorities and to plan ahead based on budget and other expectations.
• Set clear missions and objectives: Testers and clients should always agree on what the overall outcome of testing should be, and how they intend to get there. For example, they might agree to focus on testing external web application forms, and to mainly test SQL injections and that specific area of posture.
• Agree upon the best methodologies and tools: This step largely falls to testers, but again, communication is key! For instance, as discussed, a testing team might choose to observe OWASP’s “Top Ten” as a template, focusing on the biggest threats facing data-driven businesses.
• Set regular checkpoints: It’s also important for testers and clients to agree on when to meet to discuss findings and next steps. These could take place before final reports – and it’s wise to agree on one or two points of contact from either team.

Real-World Examples of Penetration Testing

One of the best examples of penetration testing success in the past few years belongs to the Canadian government. Back in 2019, poor data security saw the state expose sensitive data belonging to more than 9,000 people enrolled in a job-seeking database.

This attack prompted government officials to work with cybersecurity professionals and set up penetration testing – which identified the vulnerabilities that led to the leaks. Thankfully, these tests have helped the government make its posture more robust.

Going back to 2013, Target, the US retail giant, experienced a colossal data breach that impacted 40 million customers. While the damage was already done, penetration testing after the event revealed server insecurities and password weaknesses that the firm quickly tightened up with expert advice.

Regardless of the penetration testing types used, assessing and planning is always the best policy for protecting sensitive data.

Get Advice From the Experts

Penetration testing is an essential element of cybersecurity strategy. Organizations looking to improve their security posture should consult experienced cybersecurity professionals who specialize in ethical hacking and security assessments. Whether you require a one-time assessment or ongoing security testing, expert penetration testers can help identify vulnerabilities before cybercriminals exploit them — Get in touch with VikingCloud to learn more about how penetration testing services can strengthen your defenses.