Automated vs. Manual Penetration Testing: A Comprehensive Guide

Introduction

With technology advancing as quickly as it is and cyberattacks becoming increasingly sophisticated, it is unsurprising that automated scanning and manual penetration testing have become as crucial to business continuity as they have.

Each offers unique advantages and challenges, and the choice between them depends largely on the specific security goals, budget and resource availability, and the complexity of the digital environment being tested.

In this comprehensive guide, we’ll break down both techniques to help you understand the key differences between them so you can make informed cybersecurity decisions for your business.

What is Automated Scanning?

Automated scanning uses software to simulate attacks on digital environments, including web applications, internal and external network infrastructures, and hardware. These automated tools scan and assess the target for common vulnerabilities and report their findings.

By cross-referencing their findings against known vulnerabilities and exploits, automated scanning tools quickly perform a broad vulnerability assessment that identifies possible entry points that hackers could exploit so they can be patched.

Benefits of Automated Scanning

Speed and Efficiency

One of the major advantages of automated scanning is its speed. Automated tools can scan large environments quickly, making them ideal for identifying vulnerabilities in expansive systems.

Cost-Effectiveness

Automated scanning is often significantly more affordable than manual penetration testing, although prices for both can vary massively. That said, since by their very nature, automated scanners require minimal human intervention, the labour cost is significantly reduced.

Consistency and Repeatability

Since automated tools follow pre-defined processes and base everything on their extensive database of known vulnerabilities and exploits, they guarantee a certain level of consistency and repeatability.

Continuous Testing Capabilities

Many automated tools can be run continuously or scheduled regularly, allowing organisations to have real-time updates on their security posture and catch vulnerabilities as soon as they appear.

Problems with Automated Scanning

Lack of Contextual Understanding

Automated tools can struggle to understand complex business logic and context-based vulnerabilities. Since they focus primarily on known exploits in their database, they frequently miss more sophisticated vulnerabilities or issues that cannot necessarily be considered vulnerabilities without understanding the context of the situation.

False Positives

While automated scanning can detect vulnerabilities at scale, it often generates several false positives—vulnerabilities or security flaws that don’t actually exist or pose any real threat. This can overwhelm security, IT departments and developers as they put in unnecessary effort to address non-existent vulnerabilities.

Lack of Human Creativity

Major cyberattacks often require a lot of creativity and planning. Since automated tools follow pre-defined algorithms, they may fail to uncover attack possibilities like exploit chains that a skilled ethical hacker would.

What is Manual Penetration Testing?

Manual penetration testing involves a human pentester or ethical hacker simulating attacks on a digital environment. The pentester uses experience, creativity as well as various automated tools to exploit vulnerabilities, report their findings and offer remediation advice.

Manual penetration testing can also involve physical penetration testing, during which a pentester attempts to gain unauthorised access to a restricted area.

Benefits of Manual Penetration Testing

Deeper Analysis and Contextual Insight

Human testers can analyse digital environments and highlight vulnerabilities that automated scanners would miss due to their contextual understanding of the business. This means that more sophisticated vulnerabilities, such as exploit chains, can be flagged before they can be exploited.

Adaptability and Creativity

Manual pentesters think like actual hackers, meaning they adapt their approaches based on the responses they receive from the system. This dynamic ability allows them to mimic real-life attacks and, therefore, deliver more accurate vulnerability reports and remediation advice.

Exploitation and Remediation Advice

Depending on the type of penetration test being carried out, manual pentesters not only identify vulnerabilities and report their findings but also attempt to exploit these vulnerabilities and assess the impact of the breach. This provides significantly deeper insight into the potential danger a successful attack could cause.

Problems with Manual Penetration Testing

Time-Consuming

Unlike automated scanning, which requires minimal human intervention, manual penetration testing is very labour-intensive, which means it is significantly more time-consuming—especially on larger red teaming projects, where testing can last months.

Higher Costs

Manual testing generally involves hiring trained penetration testing experts whose services are often expensive, making manual testing less feasible for small businesses or organisations with limited resources. That said, for manual testing, cost is very contextual. Large, full digital environment testing is expensive, but smaller tests can be very manageable regardless of business size. This is why it is always advised to carry out, at the very least, an annual pentest.

Inconsistency

Since manual testing depends on the expertise and judgement of an individual, there may be inconsistencies in the approach and findings depending on the tester’s experience and methods. This is why it is always important to find companies that are NCSC-approved (National Cyber Security Centre) and CREST-accredited.

Automated Scanning vs. Manual Penetration Testing

Conclusion

Both automated scanning and manual testing have distinct advantages and drawbacks, and neither is a one-size-fits-all solution. In reality, a hybrid cybersecurity solution that utilises both is often the best approach, as their strengths and weaknesses overlap. The benefits of manual testing are usually the weaknesses of automated scanning, and vice versa.

Thanks to the significantly increased depth of manual testing, as well as the contextual understanding and lack of false positives, it is fair to say that out of the two, manual penetration testing is far more valuable than automated scanning.

But in the end, the choice between automated and manual penetration testing depends on your organisation’s goals, budget, and specific security needs. For a robust cybersecurity strategy, periodic manual tests should complement frequent automated scans to ensure that your systems remain secure against evolving threats.