Pentest vs Vulnerability Scan Explained

Many Malaysian businesses ask the same question: what is the difference between a pentest vs vulnerability scan? The two terms sound alike, yet they answer different questions. A scan tells you what might be wrong. A penetration test shows what an attacker could actually do with it.

This guide explains each one in plain language. It also shows how to choose, and how Bank Negara's RMiT policy fits in.

Pentest vs vulnerability scan: the short answer

A vulnerability scan is automated. A tool checks your systems against a list of known weaknesses and produces a report. A penetration test, or pentest, is a simulated attack. Security professionals try to break in, using the methods a real attacker would use.

Think of a house. A scan walks past every door and window and notes which ones look unlocked. A pentest tries the handles, climbs through the window and shows what an intruder could reach inside.

What a vulnerability scan does

The US standards body NIST says vulnerability scanning identifies hosts and their attributes, such as operating systems, applications and open ports. It then tries to identify vulnerabilities. Scanners are fast and easy to repeat, so they suit regular checks.

They also have limits. NIST warns that scanners can report vulnerabilities that do not exist. This is called a false positive. It advises that a person with networking and operating system expertise should interpret the results.

What a penetration test does

NIST describes a four-stage pentest method: planning, discovery, attack and reporting.

Planning agrees the scope and rules. Discovery finds targets and weaknesses. Attack tries to exploit them. Reporting records the findings and the fixes.

The attack stage is what separates a pentest from a scan. A skilled tester can combine small weaknesses into one serious path, or test how an application behaves. The result is evidence of real impact, not only a list of possible issues.

Key differences at a glance

• Method: a scan is automated, while a pentest is led by people and supported by tools.
• Question answered: a scan asks what known weaknesses exist. A pentest asks what an attacker could achieve.
• Output: a scan gives a list of findings. A pentest gives proof of impact and a fix plan.
• Timing: scans suit frequent checks. Pentests suit deeper, periodic testing.

Which one does your business need?

Most organisations need both, at different times. Scans keep watch between tests. Pentests show how your defences hold when someone really tries.

Regulation can decide for you. Appendix 5 of Bank Negara's RMiT policy document asks financial institutions for quarterly vulnerability assessments of internal and external networks that support critical systems. It also asks for annual intelligence-led penetration tests, and for tests before new systems are introduced.

When you compare providers, ask what will be in scope and how the testers are accredited. Ask whether the provider holds a NACSA licence, which the Cyber Security Act 2024 requires for penetration testing services. Also ask for a clear report with fixes and priorities, and whether the provider can retest your fixes.

Attackers do not wait for your yearly test. Breach and attack simulation, or BAS, runs safe attack techniques against your live defences on a continuous basis and maps the results to MITRE ATT&CK. It fills the gap between pentests.

How Primary Guard helps

Primary Guard offers penetration testing in Malaysia and VAPT covering web applications, networks, cloud and mobile. Primary Guard is licensed by NACSA to provide penetration testing services. For continuous checking, we provide Picus breach and attack simulation.

Not sure whether you need a scan, a pentest or both? Request your free assessment to start the conversation.

Frequently asked questions

What should a pentest report include?

A good report lists each finding, its risk level and how to fix it. Under RMiT, financial institutions must document the results, escalate them to senior management and track the fixes.

What should we include in the scope?

Start with systems that hold sensitive data or face the internet. RMiT names critical systems and digital services, including web, mobile and all external-facing applications.

Who should carry out the test?

Choose a provider with accredited testers and clear rules of engagement. RMiT expects banks to engage suitably accredited penetration testers and service providers. Ask to see a sample report first.

Key takeaway

A scan finds known weaknesses quickly. A pentest proves what an attacker could do. Use scans for regular checks, pentests for depth, and BAS to keep testing in between.

Sources

NIST SP 800-115 (Sep 2008) | Bank Negara Malaysia RMiT policy document (Sep 2026, effective Nov 2025) | NACSA – Cyber Security Act 2024, Act 854 (Oct 2026)

This article is general information, not legal or compliance advice. Check the current Bank Negara policy document and speak to your compliance team.