Network Penetration Test: Securing Your External Network

by | Jul 7, 2023 | Penetration Testing

A Network Penetration Test, or network pentest, is crucial for organizations to identify potential network security vulnerabilities. It involves a simulated cyber attack by a professional penetration tester to identify any weaknesses in the network infrastructure that malicious actors could exploit. This blog post will cover the basics of external network penetration testing, the steps involved, what is checked, and the reporting process.

What is A Network Penetration Test?

Network penetration testing, also known as network pentesting, is a type of security testing that evaluates the security of an organization’s network infrastructure. External Network Penetration Testing is a necessary process that helps organizations to identify potential vulnerabilities in their external-facing network infrastructure. This process involves simulating an attack on the network to identify weaknesses that attackers could exploit to gain unauthorized access to the network and steal sensitive information.

The primary goal of network penetration testing is to identify weaknesses in an organization’s network infrastructure before attackers can exploit them. Network pentesting typically involves a combination of automated tools and manual techniques to identify vulnerabilities in network devices, such as routers, switches, firewalls, and servers. By pentesting networks, organizations can improve their security posture by conducting this testing and protecting sensitive data from unauthorized access.

Steps Involved in Network Penetration Testing

This testing process includes several steps, each of which is important in identifying potential vulnerabilities.

1.     Information Gathering

The first step in External Pentesting is information gathering. This involves collecting as much information as possible about the target organization and its network infrastructure. The goal is to identify potential entry points for attackers, such as the organization’s website, email server, and other external-facing systems.

The information gathering process includes several techniques, such as reconnaissance and network mapping. Reconnaissance involves gathering information about the target organization from publicly available sources, such as its website or social media accounts. Network mapping includes identifying the target organization’s network infrastructure and identifying potential entry points. During this process, Open Source Intelligence is gathered first about the organization.

OSINT (Open-Source Intelligence) collects information from publicly available sources to gain insights about an organization, its employees, or its digital assets. OSINT is used extensively in various cybersecurity assessments, including Network Penetration Testing, to gather intelligence about the target organization and identify potential vulnerabilities.

Before starting an External Pentest, the penetration tester conducts OSINT to collect information about the target organization, its employees, and its digital assets. This information helps the penetration tester understand the target organization’s digital footprint, identify potential entry points, and develop a more effective testing strategy.

external network penetration test - whois

2.     Scanning

Once the information gathering process is complete, the next step is scanning. The scanning phase is one of the most critical stages in External Penetration Testing. In this phase, the pen tester uses automated tools to scan the target organization’s network infrastructure and identify potential vulnerabilities. The scanning phase is designed to gather as much information as possible about the target network and identify any potential entry points for attackers.

During the scanning phase, the penetration tester uses automated tools such as vulnerability scanners, port scanners, and network mappers to identify vulnerabilities in the target network infrastructure. These tools scan the network infrastructure for open ports, services, and applications and attempt to identify any known vulnerabilities associated with them.

The pentester may also use manual techniques to identify additional information that automated tools may not detect during the scanning phase. This may include checking for default login credentials, misconfigured services, or other potential vulnerabilities that automated tools cannot detect.

Once the scanning phase is complete, the ethical hacker will better understand the target network infrastructure and the potential vulnerabilities. This information is used to develop a more targeted and effective testing strategy focusing on the most critical vulnerabilities and entry points into the network. The results of the scanning phase are also used to validate any findings and provide evidence to the target organization of potential vulnerabilities that exist in their network infrastructure.

Nessus vulnerability scan

3.     Enumeration

The enumeration phase is the next stage in Network Pentesting, following the scanning phase. In this phase, the penetration tester attempts to gather as much information as possible about the target organization’s network infrastructure, operating systems, and applications. Enumeration aims to gain deeper insight into the network and identify additional vulnerabilities not identified in the scanning phase.

Enumeration can be performed using various techniques, including manual methods and automated tools. The security consultant can use techniques such as SNMP (Simple Network Management Protocol) queries, DNS (Domain Name System) zone transfers, service identification, and NetBIOS (Network Basic Input/Output System) queries to gather information about the network infrastructure.

The enumeration phase also involves identifying user accounts and groups on the target network. The pen tester can use automated tools to enumerate user accounts and identify the privileges associated with each account. This information can be used to identify potential attack vectors such as weak or default passwords, unpatched systems, and misconfigured security settings.

In addition to gathering information about the network infrastructure and user accounts, the enumeration phase can also involve identifying the target organization’s operating systems and applications. This information can be used to identify known vulnerabilities and potential attack vectors that an attacker can exploit.

nmap scan of network

4.     Exploitation

The exploitation phase is the third stage in External Pentesting, following the scanning and enumeration phases. In this phase, the security specialist exploits the vulnerabilities identified during the previous phases to gain unauthorized access to the target organization’s network infrastructure, applications, or data.

The exploitation phase involves using a combination of manual and automated techniques to exploit the vulnerabilities identified in the earlier phases. This may include using exploits or custom scripts to exploit known vulnerabilities, brute-force attacks to crack passwords or custom attacks.

The penetration tester can also use techniques like privilege escalation, command injection, or buffer overflow attacks to gain access to sensitive systems or applications. The exploitation phase aims to simulate a real-world attack and demonstrate the impact of the vulnerabilities on the target organization’s network infrastructure.

The exploitation phase is the most critical stage of External Network Penetration Testing as it helps to demonstrate the real-world impact of the identified vulnerabilities. It also helps the penetration tester validate the previous phases’ findings and provide concrete evidence of potential security risks to the target organization. The results of the exploitation phase are used to provide recommendations for remediation and mitigation of the identified vulnerabilities to the target organization.

SQLmap example

5.     Post-Exploitation

The post-exploitation phase is the fourth stage in Network Penetration Testing, following the scanning, enumeration, and exploitation phases. In this phase, the network penetration tester focuses on maintaining access to the target organization’s network infrastructure and expanding the penetration test scope.

The post-exploitation phase aims to simulate a real-world attack scenario, where an attacker has gained unauthorized access to the target organization’s network infrastructure and is attempting to maintain access. This involves performing additional reconnaissance and gathering information about the network infrastructure and its users, creating connections or other persistent access mechanisms, and exfiltrating sensitive data or other valuable information.

The post-exploitation phase may also involve attempting to escalate privileges, move laterally through the network, or gain access to additional systems or applications. The penetration tester may use various tools and techniques to evade detection by security controls and remain undetected for as long as possible.

network peneration test: crackmapexec tool

6.     Reporting

The reporting phase is the final deliverable of an External Network Pentesting engagement. This phase aims to provide the target organization with a comprehensive report outlining the findings, vulnerabilities, and recommendations for remediation and mitigation of the identified security risks.

The report typically includes an executive summary that provides a high-level overview of the penetration test’s objectives, methodology, and key findings. It also includes detailed technical findings that describe the vulnerabilities, their impact, and the steps required to exploit them. The report will also include evidence of the exploitation phase, such as screenshots or logs of the penetration tester’s activities.

The report also includes recommendations for remediation and mitigation of the identified vulnerabilities. These recommendations are prioritized based on their severity and potential impact on the target organization’s network infrastructure. The report also includes suggestions for improving the overall security posture of the target organization, such as implementing additional security controls, conducting security awareness training for employees, or conducting regular vulnerability assessments in addition to specific remediation steps for each vulnerability.

The reporting phase is critical in Network Penetration Testing as it provides the target organization with a roadmap for improving its overall security posture and reducing the risk of a successful cyber attack. The report’s recommendations should be implemented as soon as possible to ensure the identified vulnerabilities are remediated and the target organization’s network infrastructure is secured.

external network penetration test

The world will store 200 zettabytes (200,000,000,000- Two hundred billion TB) of data by 2025, according to Cybersecurity Ventures. This includes data stored on private and public IT infrastructures, on utility infrastructures, on private and public cloud data centers, on personal computing devices — PCs, laptops, tablets, and smartphones — and on IoT (Internet-of-Things) devices.

Areas Checked During an External Network Penetration Test

Several areas are checked during an External Network Penetration Testing engagement, including:

  • Network Perimeter: The network perimeter is the first line of defense for any organization’s network infrastructure. It is the boundary between the internal network and the external world, where most of the traffic comes in and goes out. For this reason, it is a critical area to check during an External Network Penetration Testing engagement.

The network perimeter is checked by reviewing the external-facing devices, such as firewalls, routers, and switches. Penetration testers look for misconfigurations and vulnerabilities that attackers could exploit. For example, they check for open ports, protocols, and services that should be closed or disabled. They also review firewalls to ensure that only authorized traffic is allowed into the network.

Network penetration testers use several tools and techniques to check the network perimeter. They may use port scanning tools to identify open ports and vulnerability scanning tools to identify vulnerabilities in the network infrastructure. They also perform manual testing to identify misconfigurations that automated tools may need to be aware of.

Another critical area that pen testers check is the security of remote access systems, such as virtual private networks (VPNs). Remote access systems allow employees to access the network outside the organization’s premises. However, they can be a significant security risk if not secured correctly. Penetration testers review the configuration of remote access systems from an external perspective to ensure that they are properly secured and that only authorized users can access the network.

In cloud resources, penetration testers check for several things:

  1. Misconfigurations: Penetration testers look for common misconfigurations in cloud resources that can result in data leaks or unauthorized access. For example, they check for open S3 buckets, unsecured Kubernetes dashboards, or improperly configured access controls.
  2. Vulnerable services: Cloud services have many components, such as virtual machines, databases, or load balancers, and each of these components can have vulnerabilities that attackers can exploit. Penetration testers identify these vulnerabilities and report them to the organization.
  3. Network security: The cloud network is critical to the overall security posture of an organization, and penetration testers evaluate the network security of the cloud resources. They check for open ports, protocols, and services attackers can exploit.
  • Web Applications: External web applications are commonly targeted by attackers as they are often the public-facing part of an organization’s online presence. As such, it is critical to check these web applications during a Network Penetration Testing engagement to ensure they are secure and cannot be exploited by attackers.

During an external web application penetration test, the focus is on unauthenticated testing, which means the tester has no credentials to log in to the web application. The goal is to identify vulnerabilities that attackers can exploit without logging in.

Network pen testers use several tools and techniques to check external web applications. One common tool is a web application vulnerability scanner, which automatically crawls the web application and identifies common vulnerabilities, such as SQL injection, cross-site scripting (XSS), and file inclusion vulnerabilities.

In addition to using automated tools, penetration testers perform manual testing to identify more complex vulnerabilities. This may include testing for logical flaws in the application’s workflows, analyzing the source code for security flaws, and testing for authentication and authorization bypasses.

Security consultants also test for common web application misconfigurations, such as weak passwords, default accounts, and insecure communication channels. Attackers can often exploit these misconfigurations to access sensitive data or take control of the web application.

  • Email Systems: During an External Penetration Testing engagement, email systems are important to check as they can provide attackers access to sensitive information and systems. Pentesters focus on identifying vulnerabilities in the email infrastructure that may allow attackers to compromise the system, gain unauthorized access, or steal confidential information.

One of the primary methods for checking email systems is to perform reconnaissance to identify the target organization’s email infrastructure. This includes identifying email servers, email gateways, and any email-related services. This step may also involve identifying the email clients used by employees within the organization.

Once the email infrastructure has been identified, penetration testers may perform email enumeration to identify valid email addresses within the organization. This is done by attempting to guess email addresses based on common naming conventions and using publicly available information such as employee names and job titles.


A network penetration test is critical for identifying potential vulnerabilities in an organization’s external-facing network infrastructure. Organizations can improve their security posture and protect their sensitive data from unauthorized access by checking for vulnerabilities in network infrastructure, web applications, email systems, wireless networks, and human resources.

The network penetration tester will use various tools and techniques to identify potential vulnerabilities, including scanning, enumeration, and exploitation. The goal is to identify potential entry points for attackers and demonstrate how these vulnerabilities could be exploited. The reporting phase provides an overview of the potential vulnerabilities in the target organization’s network infrastructure and recommendations for improving its security posture. By addressing the identified vulnerabilities, organizations can reduce the risk of a successful cyber attack and protect their sensitive data from unauthorized access.

Interested in conducting a penetration test for your company? Schedule a call with Artifice Security today!

Learn everything you need to know about penetration testing from our Ultimate Guide to Penetration Testing page. Artifice Security offers top-notch cybersecurity services that include penetration testing. There are several reasons why Artifice Security is an ideal choice for your organization’s pen testing needs:

  1. Knowledgeable and Experienced Testers: Artifice Security employs a team of seasoned penetration testers with a comprehensive understanding of the latest threats and attack methods. Having worked with diverse clients in various industries, our testers bring a broad perspective on security challenges and solutions.
  2. Thorough Testing: Our pen testing methodology includes all facets of your security posture. Our testers use a blend of automated and manual techniques to spot vulnerabilities and assess the overall efficacy of your existing security measures.
  3. Personalized Approach: We at Artifice Security take a tailored approach to pen testing, adapting the scope and depth of the test to align with your specific requirements. We work closely with your team to understand your goals and objectives and devise a testing plan to fulfill them.
  4. Actionable Reports: Our detailed and concise reports offer actionable insights, identifying vulnerabilities and making recommendations for remediation. Our reports are easily understandable for both technical and non-technical stakeholders, providing clear guidance on improving your organization’s security posture.
  5. Compliance: Our pen testing services align with multiple compliance regulations, such as HIPAA, PCI DSS, and GDPR. By engaging Artifice Security to perform a pen test, you can meet compliance requirements and avoid potential fines and legal troubles.

Artifice Security is a dependable and trustworthy partner for organizations prioritizing safeguarding their assets and data from cyber threats. Our in-depth knowledge, thorough testing methodology, personalized approach, actionable results, and extensive experience make Artifice Security the right choice for your organization’s security needs.

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