Internal penetration testing, or infrastructure penetration testing is a type of security test that simulates a cyberattack in which a threat actor has inside access to an organization’s systems or assets. This type of testing is crucial for organizations to identify and address potential security weaknesses that could be exploited by malicious insiders or compromised internal accounts.
Unlike external penetration testing, which tests perimeter security, the focus of internal pen tests is to identify weaknesses that a malicious insider or a compromised account might use to cause damage. A 2023 research report from Cybersecurity Insiders shows that 74% of organizations are at least moderately vulnerable to insider threats, highlighting the need for thorough internal security assessments.
An internal pen test typically follows these steps:
- Planning and scoping
- Reconnaissance
- Exploitation
- Post-Exploitation
- Reporting
Let’s dive deeper into internal penetration testing by explaining why it matters, how it works, and how you can implement it effectively to safeguard your organization’s internal network and systems.
Why Internal Penetration Testing is Crucial in Cybersecurity
Internal penetration testing provides several benefits for organizations, including:
- Identifying Vulnerabilities within the Internal Network
Internal penetration testing helps uncover hidden weaknesses within an organization’s internal systems and networks. By simulating an insider attack, it reveals vulnerabilities that external testing might miss.
- Proactive Protection against Insider Threats
Insider threats, whether from malicious employees or compromised accounts, pose significant risks. Internal pen testing proactively identifies potential exploitation points, allowing organizations to mitigate these threats before they can be exploited.
- Compliance with Industry Standards and Regulations
Many industries require adherence to strict security standards and regulations. Internal penetration testing ensures that organizations meet these compliance requirements by unveiling security flaws. Consequently, this prevents potential fines and enhances trust with clients and stakeholders.
- Enhancing Overall Security Posture
By identifying and addressing internal vulnerabilities, organizations can strengthen their overall security posture. This proactive approach not only protects against internal threats but also enhances the effectiveness of other security measures, creating a robust defense strategy.
What’s Involved?
Modern organizations have a wide range of inter-connected assets. So, an internal penetration test can explore various aspects of an organization’s internal network and systems to identify vulnerabilities and improve security. Here are some key areas that should be of particular interest, as they can present significant risks if left unchecked:
Areas Tested:
Network Infrastructure | Examines internal network configurations, routing, and segmentation to find weaknesses. |
Workstations and Servers | Assesses the security of operating systems, installed software, and patch management practices. |
User Accounts and Access Controls | Reviews the effectiveness of user permissions and access controls to prevent unauthorized access. |
| Applications | Tests internal applications for security flaws, including those that are custom-developed. |
| Data Storage and Transmission | Ensures sensitive data is securely stored and transmitted within the organization. |
Tools Used:
OP Innovate WASP | A comprehensive vulnerability assessment tool designed to identify, assess, and report on security weaknesses within an organization’s internal network and systems. |
| Metasploit | A penetration testing framework that helps identify, exploit, and validate vulnerabilities. |
Wireshark | A network protocol analyzer used to capture and interactively browse the traffic running on a computer network. |
| Burp Suite | A web vulnerability scanner used to identify security issues in web applications. |
| Nmap | A network scanning tool used to discover hosts and services on a computer network. |
White vs Gray vs Black Box Testing
Depending on the agreement between the client and testing team, an internal penetration test can have several approaches based on the level of access and information the testers have at the beginning of the assessment:
White Box Testing:
The testers have complete knowledge of the internal network and systems. They can access architecture diagrams, source code, and other detailed information, allowing for a thorough and comprehensive security assessment.
Black Box Testing:
Black box testing simulates an external attacker with no prior knowledge of the internal systems. Testers attempt to discover and exploit vulnerabilities without any internal information, simulating what an attacker might do once they’re inside the network.
Gray Box Testing:
Gray box testing combines elements of both black and white box testing. Testers have partial knowledge of the internal systems, such as access to certain documentation or user accounts, balancing realism and thoroughness.
Continual vs Manual Internal Penetration Testing
All security experts will agree that penetration tests should be conducted regularly to maintain a strong security posture. But how regular is enough? Let’s compare the differences and benefits of continual and manual internal pen testing:
| Aspect | Continual/Automated Testing | Manual Testing |
Frequency | Conducted continuously or at regular intervals, providing real-time or near-real-time insights. | Typically performed periodically (e.g., annually, quarterly), providing a snapshot of security at a specific point in time. |
Efficiency | Highly efficient in identifying common vulnerabilities quickly, thanks to automated tools and scripts. | Requires more time and effort as it involves manual inspection and analysis by skilled professionals. |
Cost | Can be cost-effective over time, as automation reduces the need for constant manual intervention. | Generally more expensive due to the labor-intensive nature of the work and the need for specialized expertise. |
Time | Provides immediate detection and response capabilities, allowing for quick remediation of identified vulnerabilities. | Slower response time due to the periodic nature of the testing, with potential delays between identification and remediation of vulnerabilities. |
Reporting | Generates standardized reports quickly, providing consistent documentation of findings and remediation recommendations. | Produces detailed, tailored reports with insights and recommendations based on the specific context and environment of the organization. |
The Internal Penetration Testing Process
At the start of this post, we briefly touched on the process steps of internal penetration testing. Now, let’s familiarize ourselves with each step in a bit more detail to get a deeper understanding:
1. Planning and Scoping
Planning and scoping set the foundation for a successful internal penetration test. This step involves defining the objectives, scope, and boundaries of the test. The testing team collaborates with the client to understand their specific needs, establish the testing timeline, and allocate necessary resources. Clear communication is essential here to ensure that all stakeholders are aligned on the goals and expectations of the penetration test.
2. Information Gathering
Information gathering, also known as reconnaissance, involves collecting data about the internal network and systems. This step includes mapping the network, identifying active devices, and gathering details about the operating systems, applications, and user accounts. Tools such as Nmap and Wireshark are often used to perform network scans and analyze traffic. The information collected during this phase helps testers understand the network’s structure and identify potential entry points for exploitation.
3. Vulnerability Analysis
In the vulnerability analysis phase, the testing team analyzes the data collected during reconnaissance to identify security weaknesses. This involves using automated tools like Nessus and OP Innovate WASP, as well as manual techniques to pinpoint vulnerabilities in the network infrastructure, applications, and configurations. The goal is to create a comprehensive list of potential vulnerabilities that could be exploited during the test.
4. Exploitation
Exploitation is the phase where testers attempt to exploit the identified vulnerabilities to gain access to the internal network and systems. This step simulates an actual cyberattack, allowing testers to assess the impact and potential damage of each vulnerability. Tools like Metasploit and Burp Suite are commonly used to exploit vulnerabilities and escalate privileges within the network. Successful exploitation demonstrates the real-world risks associated with the discovered security weaknesses.
5. Post-Exploitation
Post-exploitation focuses on understanding the extent of access gained and the potential damage that could be done by a malicious actor. Testers analyze the compromised systems to determine the depth of their penetration, the sensitivity of the accessed data, and the potential for further exploitation. This phase helps organizations understand the implications of a security breach and develop strategies to mitigate similar risks in the future.
6. Reporting
The reporting phase involves documenting the findings of the penetration test in a detailed report. This report includes an overview of the testing process, a list of identified vulnerabilities, and recommendations for remediation. The goal is to provide actionable insights that help the organization improve its security posture. A well-crafted report not only highlights the vulnerabilities but also offers practical solutions to address them, ensuring that the organization can effectively mitigate the identified risks.
Internal Pen Testing Methodology
Since penetration testing is a highly technical and sensitive process, there are established standards for ensuring consistency, accuracy, and ethical conduct throughout the testing procedure.
Though you can customize processes and procedures on top of industry methods, make sure not to stray too far from the core elements that form the standard. Common testing standards include frameworks such as MITRE ATT&CK, NIST guidelines, and the OWASP Top 10. These standards provide a solid foundation for conducting thorough and ethical penetration tests.
At OP Innovate, we have developed a unique methodology that divides our testing efforts across different stages, following an acceleration plan. This ensures a thorough and structured approach to internal penetration testing, with each stage building on the efforts of the previous one.
Here’s a breakdown of our methodology:
- Cyber Threat Intelligence (CTI) Analysis & Attack Surface Mapping
Our process starts with mapping out the attack surface of internet-facing assets and the software stack in use. This includes an in-depth analysis of the security controls and infrastructure in place. By leveraging CTI, we identify potential vulnerabilities and create a detailed view of the organization’s exposure to threats. - External Web Penetration Testing
In this stage, we utilize the insights from the CTI analysis to weaponize detected vulnerabilities. We scan all public assets and subdomains and challenge perimeter controls such as firewalls, VPNs, and office WiFi. This phase tests the robustness of external defenses, identifying weaknesses that could be exploited by attackers. - Insider Threat Simulation (Red Team) – Low Privileged Endpoint
The next phase simulates an insider threat, starting from a low-privileged endpoint. This involves testing for local privilege escalation vulnerabilities, exploiting corporate applications like Active Directory (AD), code repositories, and identity providers (IDP). Our team works to escalate privileges on a global domain level and gain access to sensitive data, such as personally identifiable information (PII) or payment card information (PCI). - Insider Threat Simulation (Developer) – High Privileged Endpoint
We then simulate an insider threat originating from a high-privileged endpoint, mimicking an internal employee from the development team. This involves lateral movement within the organization and exploiting vulnerabilities in operations technologies. The goal is to investigate weak points and attempt to access sensitive PII/PCI data, showcasing how even trusted, high-privileged users could present a security risk. - Final Detailed Report & Retest
Upon completing the testing phases, we provide a comprehensive report detailing the vulnerabilities we identified, how we exploited them, and actionable mitigation strategies. Our team offers 1-on-1 communication with your IT department to facilitate quick remediation of the issues. After remediation, we conduct a retest to ensure that all vulnerabilities have been properly addressed and that the system is secure.
This structured methodology ensures that each stage of the internal penetration testing process is handled with precision, leveraging insights from CTI to simulate real-world attacks and thoroughly assess internal security risks.
The Challenges Commonly Faced With Internal Penetration Testing
While essential for discovering vulnerabilities, internal penetration testing can bring some challenges. Collaborating with an experienced pen testing team can help minimize these challenges, which include:
Ethical and legal considerations
- Challenge: Ensuring that penetration testing activities comply with ethical guidelines and legal regulations.
- Solution: Develop a clear testing agreement with the client, outlining the scope, boundaries, and permissions. Ensure that all activities are conducted transparently and in compliance with relevant laws and industry standards.
Potential disruption to business operations
- Challenge: Penetration testing can disrupt normal business operations, affecting productivity and service delivery.
- Solution: Schedule testing during off-peak hours or maintenance windows. Communicate with stakeholders to plan and prepare for any potential disruptions. Use simulation tools to minimize impact on live systems.
Balancing thoroughness with time and resource constraints
- Challenge: Achieving comprehensive testing within limited timeframes and budgets.
- Solution: Prioritize critical systems and high-risk areas. Use automated tools to expedite vulnerability scanning and analysis. Allocate resources efficiently and consider phased testing to manage time and costs effectively.
Keeping up with evolving threats and technologies
- Challenge: Staying updated with the latest security threats and technological advancements.
- Solution: Invest in continuous education and training for the testing team. Use up-to-date tools and methodologies. Participate in industry forums and subscribe to security bulletins to stay informed about emerging threats and trends.
Internal Pen Testing with OP Innovate
Internal penetration testing is a vital component of an organization’s cybersecurity strategy. It helps identify hidden vulnerabilities within the internal network, protects against insider threats, ensures compliance with industry standards.
With years of experience in conducting penetration tests and helping clients remediate their most pressing security issues, OP Innovate is a trusted partner for delivering comprehensive and effective internal pen testing solutions.
Our PT solution is based on our WASP platform, WASP combines continuous penetration testing with attack surface management (ASM) to enable application security professionals to constantly discover, assess, and manage their internal and external exposure.
Get in touch with us today to learn how our expert team can enhance your security posture and enhance your most critical assets from potential threats.
