Legal Requirements for Penetration Testing

Certain legal regulations mandate periodic penetration tests. For instance, the Federal Information Security Modernization Act (FISMA) requires regular external penetration tests, with the frequency depending on the information type and sensitivity of the data processed, stored, and transmitted.

NIST SP 800-53 CA-8 details the penetration testing requirements for FISMA compliance. Similarly, healthcare companies must adhere to penetration testing requirements under Health Insurance Portability and Accountability Act (HIPAA.) Conducting a penetration test to ensure adherence to relevant regulations, such as the GDPR in Europe, is generally advantageous.

It is more cost-effective to proactively detect and rectify potential flaws than to bear hefty fines and loss of reputation following a breach. Even without compliance mandates, penetration testing can prove beneficial. Furthermore, penetration tests are strongly recommended at crucial junctures, such as upon reaching a significant milestone in a software development cycle or post-system implementation. And, If your company has ever experienced and rectified a breach, an additional system review can thwart potential recurring attacks by identifying alternate entry points or attack methods.

Ethical Principles in Penetration Testing

Before initiating the penetration testing process, all parties should understand these ethical considerations. A clear set of guidelines and ethical standards can help ensure that the process is effective, legal, and beneficial to enhancing the organization's security posture. Here are the seven  principles of Ethical Penetration Testing that must be observed for any pentesting engagement:

1. Informed Consent: Testing without permission is illegal, unethical, and can harm reputations. Pentesting necessitates an informed consent, encompassing awareness of methods and risks.
2. Defined Scope: A clearly defined scope ensures that penetration testers only test the systems and data that have been authorized by the client preventing testers from violating the client's privacy and causing damage. It also avoids misunderstanding.
3. Confidentiality and Data Protection: During a penetration test, sensitive and confidential information must be handled responsibly as unauthorized use or disclosure of sensitive data violates ethical and legal standards. Testers should have appropriate mechanisms to protect data during and after the test.
4. Minimizing Disruptions: While some disruption might be unavoidable during a penetration test, testers are ethically obligated to minimize the impact on operations. The testing exercise should be planned and executed to avoid unnecessary downtime or business interruptions. Adverse impacts on business operations can lead to financial losses, decreased productivity, and damage to the organization's reputation.
5. Comprehensive and Honest Reporting: Ethical testers should report all discovered vulnerabilities accurately, irrespective of their severity. Withholding information about a vulnerability is unethical and exposes the organization to potential cyber threats.
6. Support for Remediation: After completing the penetration test and reporting findings, ethical testers should offer clear recommendations and support for remediating identified vulnerabilities. It could involve providing advice on best practices, suggesting security enhancements, and helping to prioritize remediation tasks based on the severity of risks.
7. Professional Conduct: Throughout the testing process, penetration testers must maintain high professionalism. It includes respecting the client's business, maintaining neutrality, and avoiding behaviors that could exploit discovered vulnerabilities for personal gain.
   

Ethics in penetration testing are fundamental to maintaining trust between testers and organizations. Penetration testing involves authorized, simulated attacks on an organization's information systems to assess its security posture and entails significant ethical considerations that testers, stakeholders, and organizations must strictly adhere to.

Exhibit 9: Ethical Principles in Penetration Testing

Penetration Testing and other Security Assessment Types

Security assessments and testing are critical to a comprehensive Information Security Management System (ISMS). It includes methodologies such as vulnerability assessments, penetration testing, security audits, and Red, Blue, and Purple team exercises.

What are the Different Types of Penetration Testing?

Penetration testing varies regarding what is being tested and the information available to the testers. The choice of a specific method depends on your organization's needs or goals, such as budget or the type of system/network you want to be tested.

All these methods simulate potential attacks to help identify vulnerabilities that malicious actors could exploit. There are generally eight types of penetration tests:

Please note that the level of access and information (Exhibit 12) may vary depending on the client's specific engagement, scope, and authorization. The system being tested is indeed another defining characteristic of a penetration test. These systems include logical systems, physical systems, and social systems.

A penetration test may focus on computer systems, facility access controls, or employee training, depending on the system category. Penetration testing can vary between cloud and on-premises environments and may entail examining these environments either separately or concurrently.

Throughout the process, testers uncover vulnerabilities, such as logical errors in outdated networks or unauthorized system access due to misconfigured credentials and weak passwords. After gaining entry, they strive to further penetrate or access different segments. A comprehensive report is provided at the conclusion, outlining the methodologies, outcomes, and recommendations for enhancing security.

Types of Penetration Tests based on Pentesting Vectors

Understanding the different vectors or pathways through which pentesting can occur is critical for making an informed decision. Here are different types of pentests based on these vectors.

Network Services Testing

This test focuses on vulnerabilities in network services, examining components like firewall configurations, DNS, email servers, and others. This test should be a priority if your business heavily relies on its network.

Web Application Testing

Web Application penetration testing is essential if your business uses web applications, especially custom ones. It targets server-side applications, looking for flaws exploitable via the web. This type of testing is essential if your business uses web applications, especially custom ones.

Client-Side Testing

Identifies vulnerabilities in client-side software, such as web browsers, media players, and document readers. Vulnerabilities here could lead to unauthorized system access.

Wireless Network Testing

Wireless networks can have unique vulnerabilities. A wireless network test scrutinizes Wi-Fi and Bluetooth connections for security weaknesses.

Social Engineering Testing

People can often be the weakest link in security. Social engineering testing involves simulated phishing attacks, baiting, and other techniques to spot vulnerabilities in human-factor security.

Exhibit 13: Types of Penetration Tests Based on Pentesting Vectors

Understanding and selecting the appropriate penetration testing type, or a combination of tests, is essential to understanding the risks associated with organizational assets and thereby helps with risk-based security decisions.

What is Red Teaming, Blue Teaming, and Purple Teaming?

1. Red Teaming (Offensive Team)

Red teaming involves an expert cybersecurity group ethically probing a company's defenses. They identify and exploit vulnerabilities to elevate network access privileges. This simulation mimics real-world attacks, assessing a company's preventative, defensive, and recovery capabilities.

1. Identifies security blind spots
2. Evaluates existing security controls
3. Tests incident response capabilities
4. Enhances risk management strategies.

Key benefits of Red Teaming:

2. Blue Teaming (Defensive Team)

The Blue team serves as the defensive unit. This team comprises IT experts and incident response consultants who enhance the company’s network security. They employ security tools and strategies to mitigate cyberattack risks, protecting the company's critical assets and data.

Noteworthy benefits of Blue Teaming:

1. Facilitates early detection of threats
2. Improves threat intelligence
3. Enables continuous security monitoring
4. Provides training and education opportunities

3. Purple Teaming (Collaborative Team)

Purple teaming leverages the strengths of both Red and Blue teams, encouraging a collaborative cybersecurity framework. This joint exercise enables the teams to share insights - Red teams understand the system's defenses, and Blue teams learn about the Red team's attack techniques.

The benefits of Purple Teaming include:

1. Provides a holistic view of the security landscape
2. Enhances both offensive and defensive strategies
3. Improves detection capabilities
4. Encourages better coordination and collaboration

Red teaming, Blue teaming, and Purple teaming refer to different approaches and collaborative efforts in cybersecurity testing and analysis within an organization. These approaches are used to achieve different objectives within cybersecurity maturity level.By integrating Red/Blue team exercises with penetration tests, an organization can achieve a thorough, robust cybersecurity assessment, thereby bolstering its security posture.

Exhibit 16: Purple Teaming-Offensive and defensive security testing

How is Pentesting Different from Red, Blue, or Purple Teaming?

Though they share common goals, pentesting, Red, Blue, and Purple teaming differ significantly in approach and focus. Overall, these practices form a continuum within an organization's security lifecycle. While Penetration testing identifies vulnerabilities, Red teaming tests defenses, Blue teaming strengthens them, and Purple teaming integrates Blue and Red Teaming for a robust cybersecurity.

Difference between Pentesting and Application Security?

Application Security, often called AppSec, is a practice focused on making software applications more secure by identifying, fixing, and preventing vulnerabilites. It includes various activities like threat modeling, code reviews, and vulnerability scanning. The aim is to prevent security incidents by tackling issues like cross-site scripting (XSS), injection attacks, and other threats at the application level.

Security controls, or countermeasures, are an integral part of application security. These include firewall systems, anti-virus/malware software, encryption programs, biometric authentication systems, and more. Yet, these measures alone do not guarantee complete protection. The security of the application's source code is vital. A small defect in the code can leave an opening for attackers to exploit, potentially leading to data breaches.

This risk is particularly relevant for organizations migrating their data to cloud-based applications, which are more accessible to attackers due to their internet-facing nature. Contrarily, Penetration Testing is a practice where ethical hackers attempt to breach an organization's security systems. The objective is to uncover vulnerabilities and weaknesses that malicious hackers could exploit.

The main distinction between AppSec and Pentesting lies in their focus. AppSec is concerned with building secure applications, whereas Pentesting tests the security of those applications and the broader system.

AppSec strategies often utilize several tools to enhance software security:

1. Dynamic Application Security Testing  (DAST)

This tool simulates attacks on a web application to identify vulnerabilities, particularly those related to input validation or manipulation.

2. Static Application Security Testing(SAST)

Without running the application, this tool scans the source code to detect potential security flaws before deployment.

3.Software Composition Analysis (SCA)

This tool is useful for identifying risks associated with using third-party applications or open-source code.

4. Interactive Application Security Testing (IAST)

Combining aspects of DAST and SAST, this tool analyzes applications in real-time, catching vulnerabilities that other tools might have missed.

Application Security and Penetration Testing are complementary strategies. Secured applications are built via deploying AppSec measures, and their security is subsequently tested through Pentesting.

Penetration Testing Tools and Platforms

A variety of robust tools and platforms are at the disposal of cybersecurity professionals conducting penetration testing exercises. These range from open-source software to commercial products, each boasting unique features and capabilities. Exhibit 19 outlines some commonly employed platforms and tools in the penetration testing field.

Despite these tools' prowess in identifying vulnerabilities, skilled professionals must interpret the results and devise effective solutions. Hence, a solid understanding of system security, networking, and application architecture is essential for effective penetration testing.

Penetration Testing Methodologies

At the heart of Penetration Testing practice lie methodologies, which, when wielded by skilled professionals, pave the way for comprehensive security assessments. Understanding the standardized methodologies that guide the execution and evaluation of these tests is not less important.

Penetration Testing Standards

Many standardized testing methodologies have surfaced in the penetration testing realm over the years While some were created to address specific requirements, like the PCI-DSS Penetration Testing Guidance documents, others aim to standardize previously divergent testing processes.

Some widely recognized methodologies include the Open Source Security Testing Methodology Manual (OSSTMM) and the Penetration Testing Execution Standard (PTES). Additionally, several groups like OWASP and NIST have compiled their guides. Though slight differences exist among these methodologies, they generally share a similar foundation.

These methodologies have distinct characteristics regarding testing content, the importance of elements tested, and measurement and reporting of results, though they share certain aspects. While not exhaustive, they are vital guidelines that help ensure a system is reasonably secure by providing a security benchmark. They are designed to boost system security and equip individuals with a foundational understanding of executing and assessing pentesting effectively.

General Penetration Testing Methodology

Penetration testing or pentesting is an intricate process where security professionals deploy various tools, practices, and strategies to identify gaps in networks, devices, applications, and infrastructure's security posture. The resulting insights offer valuable glimpses into the organization's security posture.

Upon remediation, the pentesting team reassesses the IT environment to ensure vulnerabilities have been properly addressed and may conduct follow-up tests to identify any new or overlooked vulnerabilities. The Pentesting methodology (Exhibit 21) can be broadly classified into 3 stages :

1. Pre-Engagement

Before a Pentesting engagement, organizations, and testers establish mutual understanding through NDAs (Non-Disclosure Agreements) to protect sensitive information and Rules of Engagement (RoE) to define the test’s scope, methods, timeline, and limitations, ensuring controlled and non-disruptive testing.

2. Engagement

The Engagement stage is a multi-step process. Starting with information gathering and scoping to establish objectives and gather data about the systems to be tested. The engagement stage is most crucial as  it involves collecting information without direct contact with the target systems.

Post information collection and investigating the network, pentesters design attacks based on the insights gathered to exploit and attempt to penetrate the system while recording the process and any alterations made. The final reporting phase includes sharing findings, recommendations, and follow-up actions with the client.

Exhibit 21: General Penetration Testing Methodology

3. Post Engagement

After completing the penetration test, the organization enters the critical Post-Engagement stage. This phase is essential for ensuring that the insights and recommendations derived from the test are effectively utilized to bolster the security posture. Once the penetration testing report is received, the organization analyzes the findings. It's important to understand the implications of each vulnerability, particularly about the organization's specific context and threat landscape.

Based on the severity scores and descriptions provided in the report, the organization prioritizes which vulnerabilities to address first. Typically, those with the highest severity are given precedence. Special attention may be paid to segmentation testing details to ensure no unauthorized access paths are available. The organization works on fixing the identified vulnerabilities that may involve patching software, reconfiguring security settings, strengthening access controls, or implementing additional security measures. Once the remediation efforts have been carried out, the penetration testers retest the systems with a focus on the previously identified vulnerabilities to ensure they have been properly addressed.

Finally, the organization documents all the actions taken including the remediation efforts and retesting results. This documentation is crucial for compliance, especially in cases where there are regulatory requirements like PCI DSS, which mandates the remediation of critical and high vulnerabilities on internal networks and critical, high, and medium vulnerabilities on internal networks and critical, high, and medium vulnerabilities on externally facing systems. From organizational perspective, it is a good practice to conduct a "lessons learned" session to discuss what went well and what could be improved for future penetration tests. It helps in enhancing the efficiency and efficacy of future engagements.

Cyber Kill Chain and Attack Simulations

In Penetration Testing, Cyber Kill Chain and Attack Simulations involve structured frameworks for understanding and simulating cyberattacks to identify vulnerabilities and fortify defenses. The concept is derived from the military term "kill chain," which outlines the structure of an attack from target identification to the final action. In cybersecurity, models like the Lockheed Martin Cyber Kill Chain, the MITRE ATT&CK Kill Chain, and the Unified Kill Chain have been developed to represent the stages of a cyberattack.

These models offer a systematic approach to comprehending an attacker's tactics, techniques, and procedures (TTPs) and act as guides for simulating cyberattacks in a controlled environment. They are invaluable in understanding an attacker's sequence of steps and identifying and reinforcing defenses at each stage. Pen testers utilize the TTPs of threat actors to simulate attacks, and each stage of the models represents a point where the system can be tested and strengthened. Kill Chain models help businesses and security organizations identify vulnerabilities and develop effective mitigation strategies.

1. Lockheed Martin Cyber Kill Chain

This framework identifies vulnerabilities and breaches and examines the effectiveness of existing controls. It includes the following phases:

1. Reconnaissance: Information gathering using available resources.
2. Weaponization: Creation of a malicious payload using platforms and applications like malware, a compromised document, or a phishing email.
3. Delivery: Transmission of the payload directly to the target.
4. Exploitation: Attackers prime the execution of their mission to infiltrate and compromise systems.
5. Installation: Attackers gain access and establish a foothold in the targeted environment.
6. Command and control: The infected system "calls home" to a control system, allowing the attacker to obtain remote control.
7. Actions on objectives: The final step where attackers, with direct access, can achieve their objectives, such as data exfiltration​.

2. MITRE ATT&CK Kill Chain

This model documents TTPs (tactics, techniques, and procedures) used in advanced threats. It is divided into two focus areas: Pre-ATT&CK and ATT&CK, the latter focusing on steps taken after an attack is launched.

The framework helps organizations understand and prevent business threats, including reconnaissance, lateral movement, and privilege escalation. It also considers the impact where threat actors disrupt availability or compromise integrity. A variant of this model, Mobile MITRE ATT&CK, describes how an attacker might manipulate traffic to and from a device if they cannot gain direct access to it​.

3. The Unified Kill Chain

This model addresses the scope limitations and time-agnostic nature of the previous two kill chains. It captures the nuanced behaviors of attackers across 18 different attack phases, grouped under three areas of focus:

1. Initial foothold: Attackers put most of their effort here to gain and maintain a foothold.
2. Network propagation: Attackers move past the entry point and search for anything of value.
3. Action on objectives: The attacker prepares to execute the main objective once they find what they seek​.

Relevance of Kill Chain Models in Penetration Testing

Kill chain models in penetration testing are highly relevant for the following reasons:

1. Framework for Assessment: They offer a structured approach to assess vulnerabilities at different stages of an attack. For example, during the reconnaissance phase, pen testers can evaluate the availability of public information that could benefit an attacker.
2. Understanding Attacker Tactics: Kill chain models help comprehend the tactics, techniques, and procedures (TTPs) of threat actors, enabling pen testers to anticipate their actions and unearth otherwise hidden vulnerabilities.
3. Enhancing Defense Mechanisms: By identifying weaknesses in current defenses by understanding each attack phase, organizations can bolster specific defenses. For instance, focusing on robust email filters and keeping software updated in the delivery and exploitation stages can mitigate phishing and exploitation attempts.
4. Reporting and Communication: These models serve as a common language, simplifying discussions on findings, implications, and remedial strategies among technical and non-technical stakeholders.
5. Evaluating Pen Test Effectiveness: Mapping a penetration test to the kill chain stages allows organizations to measure the depth to which a simulated attack could penetrate, gauging the efficacy of the pen test and existing security measures.

It is crucial to recognize that while valuable, kill chain models are not exhaustive and should be employed alongside other security practices and frameworks, as they mainly concentrate on external threats and might not adequately address elements like insider threats or user awareness and training.

The Penetration testing procedures

Penetration tests usually progress through seven distinct stages. However, some practitioners may combine or divide steps further for specific scenarios.

Exhibit 23: The 7 Stages of Penetration Testing Procedure

How to choose the right penetration test for your Organization?

The decision on the right penetration test involves understanding various types of tests, your business environment, compliance obligations, risk tolerance, budget, and past security incidents. By evaluating these factors, you can make an effective choice that enhances your security and protects your company from cyber threats.

It's worth noting that a combination of different tests often provides the most comprehensive insight into your security posture. Following sections provide a guideline to assist you in making an informed decision:

All these scenarios present valid reasons for scheduling a penetration test. However, the specific reasons can influence the objectives and the course of the test. By outlining these considerations, you can make informed decisions and streamline your interaction with penetration testing service providers.

Key considerations for Penetration Testing

Ensuring the chosen penetration test aligns with your company's needs is vital. Ethical hacking is as varied as development, with certain companies specializing in hardware and firmware testing, cloud penetration tests, Active Directory tests, physical security, and social engineering.

The following factors need to be considered for an effective penetration engagement:

1. Business Environment

Consider the nature of the data your company manages. For financial information, prioritize network and web application testing. For sensitive personal information, client-side and social engineering tests may be vital.

2. Compliance Requirements

Certain industries and data types have specific compliance standards. For instance, companies processing card payments must adhere to PCI-DSS, which necessitates specific types of penetration testing.

3. Risk Tolerance

Different companies have varying risk tolerance levels, which can influence the frequency and types of penetration tests conducted. Depending on the risk tolerance, a company's requirements may be satisfied with the pentesting of a segment rather than the whole system.

4. Budget

Penetration testing is an investment in your security. As with any investment, consider your budget. Understanding your security needs and risk profile will help in effective resource allocation.

5. Past Incidents and Vulnerabilities

Information about past breaches or known system weaknesses can guide the choice of penetration tests. Not all penetration testing teams offer identical services. It's incumbent upon your company to identify the team that best fits your needs.

How to find the right partner for Pentesting requirements?

Choosing the right partner for your penetration testing needs involves careful consideration. The right partner can deliver expert assessments, identify vulnerabilities, and provide end-to-end solutions.

1. Expertise: The potential partner should be adept at addressing your specific areas of concern. While most companies offer network and web application testing, some may specialize in areas like hardware or physical testing. Choose a partner with the right expertise.
2. Test Methodology: Understanding a potential partner's testing strategy or methodology is crucial. This insight can clarify their approach to penetration testing and whether it aligns with your requirements.
3. Initial Meeting and Agreement: After shortlisting a company, discuss the scope and rules of engagement. It includes costs, specific areas to be tested, and techniques to be used during the test.

It's important to align your needs with the partner's capabilities and approach. A thoughtful evaluation will ensure you find the best fit for your organization. Though not exhaustive, Exhibit 24 provides a list of questions to vet penetration testing service providers.

The different models of Penetration Testing as a Service (PTaaS)

Penetration Testing as a Service (PTaaS) enables companies to outsource vulnerability assessments to external experts. This model benefits businesses without in-house penetration testing capabilities, offering scalable and cost-effective solutions. Exhibit 25 shows different PTaaS Models.

Exhibit 24: Questions to qualify a Pentesting Vendor