What are the Processes in an Internal Network Penetration Test?

by | Sep 26, 2022 | Penetration Testing

The greatest offensive is a good defense. It would be best to think about the other side’s attack tactics first. Penetration testing, often known as pentesting, is a technique used in cybersecurity to identify network defects attackers may use. In 2021, there were nearly 1,900 successful data breaches in the U.S. alone. Every day since 2013, cybersecurity breaches have stolen an estimated 3.8 million records. We must acknowledge that there are far more vulnerabilities than ever because today’s complicated cyber security environment houses constantly evolving threats.

Organizations must be proactive in implementing a penetration testing program alongside their vulnerability management program to produce mature cybersecurity solutions and enable them to function to their full potential. A company must conduct an internal penetration test after realizing that these programs are essential to deploy. Any hands must be on deck during these internal network penetration tests to adequately record all known vulnerabilities and the steps a business must take to close such flaws. Without further ado, let’s examine how to conduct an internal network penetration test and why your company may require one more often than you think.

Internal Network Penetration Test

Like an external penetration test (pentest), an internal network penetration test is a test against your organization’s internal systems. The external and internal network penetration tests can be done using either a black, white, or grey box technique. Black box testing methodologies require the attacker to have little to no knowledge of the organization’s current security structure.

Internal network penetration testing may comprehensively evaluate vulnerabilities, passwords, network settings, and internal monitoring. During the internal network penetration test, the security engineer will either be on-site or use a remote virtual machine (VM) to conduct the penetration test. In real life, a malicious actor takes control of an internal asset and exploits it, which is an actual situation that often occurs in businesses. This malicious insider may be a current or former employee or a third party that took advantage of a current employee’s irresponsibility to get login information for an internal system.

An external pentest mimics an attack on the company through an internet connection. At the same time, a security engineer carries out an internal network penetration test inside the host security system or building access system. It requires a concerted effort on the attacker’s part to access unlawful resources because of the closed-quarters attack measurable in place. Because of this, the support team’s job becomes crucial for identifying organizational weaknesses and tracking the attacker’s progress.

The attacker must locate the particular network authentication credentials that provide them administrator access after they have connected to an active network port from the internal network. Since they don’t have a firewall to slip past, a malicious actor might carry out much more swiftly, allowing the attacker more time to exploit any weaknesses that may be there. This type of attack effectively opens all doors in their favor. The most dangerous aspect of an internal attack is the assumption that the attacker, in these cases, already has thorough insider knowledge of the locations of desired data on the network. External attackers often are unaware of this privilege at the outset of their exploitation operation(s).

Checklist for Internal Network Penetration Test

According to a 2015 study, 92% of companies with cybersecurity programs use penetration testing services. A penetration test would help 35% of the respondents to this poll lower the risks in their network architecture. Organizations should think about assessing their cybersecurity efforts from the viewpoint of an attacker who has already acquired access to the internal network, whether it’s a malicious insider or just a careless employee who exposes your firm to a phishing attempt. An internal network penetration test might be helpful in this situation. Let’s go through the precise sequence of actions that your firm must follow while executing an internal network penetration test to protect it against internal threats:

  1. Preparation
  2. Identify Vulnerabilities
  3. Exploitation
  4. Reporting


You must complete the internal penetration testing checklist to prepare for this test. Let’s start with preparation, which calls for you first to arrange technical points of contact that the team may utilize before, during, and after the start of the testing. To guarantee that all obligations kept within the scope of the test are satisfied, your firm must choose the internal point person who will be on call throughout the test. Once your organization finds this internal point person, you would need to deploy a team compatible with the test. Your business can enable an efficient communication channel throughout the security evaluation if this alignment is in place.

Once your company sets up the team, the preparation must explain how the test’s scope and objectives align with the organization’s highest-priority business objectives. Your company must select the permissions and access controls the pentester must get before executing the test once your team has established the scope.

The next stage is to draft a formal permission contract with the pentester, which you must sign before the penetration testing services team carries out the pentest. Your company must obtain everything you expect to be done in writing for a formal agreement to guarantee everyone is on the same page. An internal pentest is essentially the imitation of a cyber-attack. The pentester and senior staff should have a thorough conversation at this last stage of preparation to determine which components of the organization’s systems the penetration tester examines and which are not.

Identify Vulnerabilities

After the internal pentest starts, the pentester will look for any vulnerabilities using various tools and techniques (the same ones that malicious attackers effortlessly deploy). The pentester will now look for any vulnerabilities in the internal IT systems that the consultant might exploit to compromise the network’s integrity. The penetration testing consultant will carry out advanced approaches and analyses using the penetration testers’ access to a guarded system to quantify the potential harm each vulnerability might create. The penetration tester keeps track of the origin of each vulnerability, enabling the business to fix each flaw.


Organizations that want to simulate the behaviors of an actual attacker who exploits network security flaws without suffering the long-lasting impacts of exploitation should conduct internal pentesting. Internal pentesting exploitation techniques have developed along with the attack strategies used by hackers. Exploitation is a task designed to find possible cybersecurity software holes that the IT team may fix once the test has started to confirm they are there. In these real-life (as opposed to pentest) situations, a malicious actor will often take sensitive data from research files, business finances, or client payment information. The penetration testers will simulate an actual inside attack that aims to get essential data and corporate information while covering their traces, so the firm won’t discover who was responsible for the breach.


Ultimately, depending on the overall security of their internal IT, an internal pentest may provide enterprises a quick snapshot of the significant vulnerabilities to their network architecture. After the pentest team finishes the internal pentest, the pentester and security team must disclose their results to senior employees (and maybe the board and stakeholders) and create a strategy to address the vulnerabilities. The final report will evaluate the network’s overall health and include suggestions for stopping the malicious attackers from carrying out the actions they performed throughout the test. The pentest team will create these reports in a manner that gives priority to fixes for the discovered vulnerabilities.

How to Prevent Internal Threats

One analysis claim that it takes American businesses an average of 287 days to find a network breach, with an average time to contain a breach being 80 days. Companies must be proactive in patching their security vulnerabilities far before a hostile attacker takes advantage of them since more modern hackers use “internal tactics” to infiltrate businesses. The company may take a “defense-in-depth” approach to information security by implementing internal and external security measures, which remove blind spots and weaknesses.

The purpose of the internal pentest is also to evaluate the Intrusion Detection System (IDS) and the anticipated employee reaction if the security team discovers a malicious attacker on the network. Even if your company is likely to have rogue workers, it is crucial to maintain the security of your vital internal systems in case one wanders in. Whatever the attacker’s origin, it is inevitable that they have a variety of goals and tactics, which might make them challenging to predict. To prevent potential attack vectors from being utilized, security teams must be aware of any weak areas in the authentication of employees for access to critical corporate data.

The reality is that increasingly modern hacks don’t seem to represent threats from outside sources. They resemble internal users abusing systems and services more than external ones. Security teams risk the attacker compromising their system using phishing tactics to access critical systems covertly unless they are focused on their network security policies. The company may prepare a defense against any hacking attempt using the data acquired from the security assessment. Internal pentests may look for setup errors, such as errors in error handling, that can enable staff members to access and unintentionally expose information online. Artifice Security advises internal testing as often as your company runs external pentests since user privacy and data security are major concerns.

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Final Thoughts

Organizations sometimes neglect internal network penetration testing. Because an external pentest is more common due to concerns of external threats, internal pentests don’t get the same amount of attention as external pentesting. Companies may believe that an internal pentest is unnecessary if they can fix any security flaws discovered after an external pentest on their external network.

An internal pentest ought to be used as a type of quality assurance (QA) test because it offers the organization a thorough examination of any potential weaknesses in network architecture and design, operating system (OS), and web application configurations, as well as the necessary insight into human behavior. Your company may rest easier knowing that internal IT security is much better today when a trusted third-party pentest company carries out internal pentesting following the appropriate steps in the checklist we have outlined above. Contact Artifice Security right now for additional details on how to get an internal network penetration test for your business.

Want to learn more about penetration testing services? Visit our Ultimate Guide to Penetration Testing page.

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