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Internal Penetration Testing vs External Penetration Testing

External Penetration Testing

External Penetration Testing

Data security is top of mind for businesses today as they look to avoid becoming the next victim of cybercrime. In an increasingly remote and networked world, hackers are constantly on the lookout for vulnerabilities that leave businesses wide open to attacks.

By now, most companies have a strategy when it comes to policies and security controls for preventing data breaches, but they don’t all put their data security to the test. That’s where penetration testing comes in.


Internal vs External Pen Testing

Penetration testing (often shortened to “pen testing”) is a series of tests by penetration testers, sometimes called ethical hackers, that involves simulating an attack and attempting to gain access to your systems. The goal is to identify information security risks and find vulnerabilities that could be exploited by cybercriminals and other threat actors.

The 6 major types of penetration tests include:

  1. Network infrastructure tests
  2. Wireless network tests
  3. Application and API reviews
  4. Remote work assessments
  5. Web application tests
  6. Firewall configuration reviews

And, some of the vulnerabilities that can be exposed during penetration tests are:

  • Ineffective firewall rules
  • Unpatched systems
  • Software vulnerabilities
  •  Insecure configuration parameters
  • Inadequate encryption protocols
  • Weak security controls

While penetration testing is an important part of the security posture of any business, industry regulators in fields such as financial services, government and healthcare consider it so important to data security that it’s a mandated requirement in a company’s security program.


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External vs Internal Penetration Testing: Explaining the Difference

To fully understand penetration testing, it’s important to know that it can be broken into two distinct types: external penetration testing and internal penetration testing.


External Penetration Testing

External penetration testing tests the business assets that can be seen from the internet. In an external penetration test, penetration testers will try to access internal networks and data through vulnerabilities in a company’s assets they can access externally, such as a website.

An external network penetration test is initiated by gathering information and intelligence, which can include everything from looking for open ports, to tricking employees for passwords to access your systems. If the penetration tester gains access to the company’s internal network, this would increase the criticality of any findings from the internal penetration test.


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Internal Penetration Testing

An internal penetration test takes a full security assessment of the company’s internal systems. This assessment includes vulnerability scans to find out how far an accomplished attacker could move through your network and access your data after initial internal access is achieved.

If a tester gains access to your network through an external penetration test, they will use this initial access to collect information, attempt to escalate privileges and spread their access to other internal assets and applications.

Alternatively, the pen testing team can request for the client to connect a device directly into the internal network to bypass the need for external testing and get straight to work on the internal tests. This device is configured to provide reliable remote connections for the testing to be completed.

During an internal penetration test, the tester will gather intelligence and then attempt all known exploits to see how the security controls operate against potential attacks and breaches. One of their main tactics will be finding vulnerabilities that allow them to take admin control of a domain.


Comparing Penetration Testing (Internal vs External)

When comparing internal vs external penetration testing, it’s important to remember that doing one doesn’t mean you can forget about the other. Both are critical in exposing vulnerabilities in your networks, because even the best external defenses have workarounds and even with the best internal security you don’t want malicious actors strolling into your network through external assets.

The consensus on internal and external penetration testing is that they should be performed annually and when your system undergoes critical updates. The reason for this is that you want to ensure that your business networks remain secure in the face of evolving cybersecurity threats and also when new technologies are being introduced to your system.

It’s an easy thing to put off, but a lack of regular penetration testing is virtually guaranteed to leave your business wide open to attacks.


Choosing the Right Security Team to Perform Your External or Internal Penetration Testing

Now that you understand the basic differences between internal and external penetration testing, the next step is to consider how you will carry out penetration tests and who will do them.

They can be performed by internal testing teams made up of your in-house IT staff, but many businesses find that third-party testers can be relied on to give an unbiased, objective assessment because they will not be held accountable for gaps in the security posture.

Also, while it’s true that penetration tests can be performed remotely via VPN, it’s recommended to do them on-site to ensure the testers are getting a full, unobstructed view of your network.

This is another key advantage to deploying devices remotely on a client’s internal network. The penetration testing team can perform testing remotely with internal access, without needing physical access.

Internal Penetration Testing

Internal & External Penetration Testing: 5 Main Steps

Whether you choose to go with an in-house penetration test or a specialized provider, there is a tried and tested approach to pen-testing that should be followed:

Scoping: Begin by ‘scoping’ your network and infrastructure to determine what needs to be included in your assessment strategy. The scope should include details such as the number of internal and external IPs, subnets, and physical locations.

Reconnaissance: Penetration testers need to spend time learning about your systems so they know where to attack. The best testers will use the most advanced intelligence-gathering techniques. This phase can be shortened if the penetration team can gain an understanding of the in-scope assets and networks from the client’s IT team.

Vulnerability scanning: Once they know what they’re up against, penetration testers can use vulnerability scanning tools to expedite the process of exposing security weaknesses and finding exploits.

Exploitation: The next step is to see how well those exploits work in a way that will not actually disrupt your business. At this stage, a pen tester might attempt to execute code on an unpatched server, bypass a fragile key card system, take advantage of weak password control, or fool an impressionable employee.

Reporting: When the penetration testing is complete, the testers put together a comprehensive assessment that details where they found vulnerabilities if they were able to exploit them, and how they can be remediated.


Internal vs External Penetration Testing: Choosing the Right Cyber Security Firm

Now that you know the basics of internal and external penetration testing, we’d love to help you learn more.

CP Cyber’s penetration testing services are delivered by best-of-the-best certified ethical hackers, with more than 45 years of combined cybersecurity experience from fields such as military, government agencies and big four consulting firms.

We make use of cutting-edge penetration testing techniques such as DNS and ARP poisoning, MitM network sniffing, SNMP modification and VLAN hopping, and provide you concise, actionable remediation recommendations to help you close the gaps in your cybersecurity and remain safe.

Book a meeting with us today to go over your external or internal pen-testing needs, and we will identify security gaps in your network together.

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