Understanding internal vs. external penetration testing: which is best for your business?

In this blog, we will help you understand the differences between internal and external penetration testing and how to choose the best approach for your industry.

Penetration testing, or pen testing, is key in helping businesses find and fix vulnerabilities before attackers can exploit them. There are two main types of pen testing: internal and external. Let’s take a closer look at each, their benefits, and how they can help different industries.

What is internal pen testing?

Internal pen testing checks for vulnerabilities from within the organisation’s network. It focuses on the risks posed by employees or others who have access to sensitive systems and data. Testers know a lot about the organisation’s setup, which helps them do a thorough job.

What are the benefits of internal pen testing?

1. Spotting insider threats

It helps find vulnerabilities that could be exploited by people inside the organisation, like employees or contractors, who might misuse their access.

2. Checking internal security

Internal pen testing can help businesses reach their SOC 2 compliance goals, as it identifies vulnerabilities, strengthens the company’s security, shows due diligence, builds client trust, meets compliance requirements, and supports continuous improvement.

3. Meeting rules and standards

Many industries have rules that require internal pen testing to make sure companies are keeping their systems safe and meeting standards.

What industries benefit from internal pen testing?

Businesses of all sizes and across various industries can benefit from internal pen testing. Here are some key sectors:

Financial services

Banks and insurance companies deal with lots of sensitive customer data, so they need to watch out for insider threats to keep that data safe.


As electronic health records become more common, healthcare providers must ensure patient data is protected from unauthorised internal access.

Government agencies

Governments deal with a lot of sensitive data, so they must secure their networks against internal risks that could leak classified information.

What is external pen testing?

External pen testing looks at vulnerabilities from outside the organisation’s network. Testers act like hackers trying to break in from the internet, without knowing much about the organisation’s systems beforehand.

What are the benefits of external pen testing?

1. Finding outside threats

It helps uncover weaknesses that hackers could exploit to get into an organisation’s networks or steal data.

2. Checking perimeter security

It shows how well security measures like firewalls and intrusion detection systems are working to stop external attacks.

3. Managing third-party risks

Many rules and standards require external pen testing to make sure that vendors and service providers don’t pose a risk to an organisation’s security.

What industries benefit from external pen testing?

Businesses of all types and sizes in different industries can benefit from external penetration testing. Here are some examples:

Ecommerce and retail

Online stores store a lot of customer data, so they need to make sure their websites and payment systems are secure from outside attacks.

Technology and software development

Tech companies need to protect their intellectual property and customer information from hackers who could exploit vulnerabilities in their products or services.

Critical infrastructure

Industries like energy and transportation rely on complex systems to deliver essential services. External pen testing helps them find and fix vulnerabilities that could be exploited to disrupt operations or cause harm.

In summary, both internal and external pen testing are crucial for keeping businesses safe from cyber threats. Internal testing focuses on insider risks and internal controls, while external testing looks at vulnerabilities from outside the organisation. By using both approaches, businesses can stay ahead of attackers and protect their data, systems, and reputation.

if your business needs a penetration test or you want to learn more, get in touch here.

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