Advisory

Network Penetration Testing: External and Internal

CREST-accredited testing of your internet-facing perimeter and your internal network, run by testers based in Australia.

Network penetration testing in Australia, from the perimeter in.

Network penetration testing shows what an attacker can reach on your network and how far they can get. An external test looks at everything you expose to the internet, while an internal test starts inside, the way a rogue insider, a stolen laptop or malware would. Vectra is a CREST-accredited penetration testing provider, operating since 2001, and our testers are based in Australia and work nationally. We prove every High-severity finding by hand and show you how to fix it. Many organisations book external and internal testing together, so one report follows the attack path from the internet to their most sensitive systems.

Network Penetration Testing

What a network penetration test involves.

Topic What to expect
Accreditation CREST-accredited penetration testing provider
Scope External, internal or both, plus servers, containers and backup systems
Starting point The open internet, a user account, or an assumed-breach foothold inside the network
Method CREST-aligned six steps, with every High-severity finding proven by hand
Delivery Testers based in Australia, working nationally, on site where the test needs it
Deliverables Executive narrative, technical findings, ranked fix roadmap and engineer debrief
Retest Retest of every High-severity finding and above
Quote Scoped and quoted to your IP ranges, sites and goals

External penetration testing: what an outsider can reach.

An external penetration test looks at your network the way an attacker on the internet sees it. We start with what is public, then try to turn exposed services into a way in.

Book one when you publish new services to the internet, change firewalls or remote access, or want independent assurance about your perimeter.

  • Perimeter and exposed services

    We map every live host and open port in your public ranges, then test each service for weak configuration, outdated software and default passwords.

  • Remote access and VPN

    VPN concentrators and remote desktop gateways are prime targets, so we check how they sign people in, how well they are patched and what information they expose.

  • Email and DNS

    We look for mail and DNS settings that make spoofing easier, leak internal names or let someone take over a forgotten subdomain.

  • Cloud-exposed assets

    Most perimeters now include cloud hosts and storage. We include the public parts of your cloud estate, and tell you when a full cloud test is worth it.

Internal penetration testing: how far an intruder can get.

An internal penetration test starts from a foothold inside your network. That might be a staff laptop, a spare network port or a standard user account, and from there we try to reach the systems that matter most.

This is the test that demonstrates how one phishing click or stolen password becomes a breach, and it also checks whether your network zones really hold.

  • Active Directory attack paths

    We map the trust and permission paths in Active Directory. We test common attacks such as Kerberoasting, weak service accounts and unsafe delegation.

  • Privilege escalation

    We look for ways to turn a standard account into an administrative one, first on individual hosts and then across the domain.

  • Lateral movement

    We test how easily an attacker can move from one machine to the next, using reused passwords, open shares and built-in administration tools.

  • Segmentation testing

    We verify that firewalls and network zones block what they should, and for PCI DSS this covers the segmentation testing in requirement 11.4.5.

  • Assumed-breach start

    To save time, we can start from a device or account you give us, so the test spends its effort on what happens next.

An external test asks who can get in. An internal test asks how far they get.

Serious attacks often combine both, so testing them together reveals the complete path, from an exposed service or a phished user to your most sensitive systems.

Our network penetration testing methodology.

Every network pen test follows our CREST-aligned six steps. This is what each step means on a network.

  1. Step 1: Scope and kick-off

    We confirm IP ranges, sites, test windows and rules of engagement, and you name the people we call if something looks wrong.

  2. Step 2: Threat modelling

    We agree which attacker to copy and which targets matter most, such as domain admin, payment zones or backup servers.

  3. Step 3: Reconnaissance

    We map live hosts, open ports and running services, working from what an attacker can see rather than from your asset register.

  4. Step 4: Exploitation

    We test each weakness by hand, and every High-severity finding and above gets a proof-of-exploit with full evidence.

  5. Step 5: Post-exploitation

    We pivot, escalate and cross network zones to measure the blast radius, and we note where your monitoring should have seen us.

  6. Step 6: Reporting and retest

    You get the written report, a debrief with your engineers and a retest once the serious findings are fixed.

Infrastructure penetration testing: servers, containers and recovery.

Servers and operating systems

We test Windows and Linux servers for missing patches, weak settings and risky services, and we check who can log on and with what rights.

  • Patch and configuration gaps
  • Local privilege escalation
  • Risky services and open file shares

Active Directory tiering

We review how administrative rights are separated into tiers, because when tiers mix, one stolen login can unlock the whole domain.

  • Admin tier separation
  • Kerberoast and delegation chains
  • Service account exposure

Containers and Kubernetes

We assess container platforms and Kubernetes clusters, covering runtime settings, secrets and who can reach the control plane.

  • Cluster and node set-up
  • Secrets and service accounts
  • Paths out of a container

Backup and recovery

Attackers target backups to stop you recovering, so we check whether backup and recovery systems can be reached or changed from the wider network.

  • Backup server exposure
  • Access to recovery consoles
  • Recovery path checks

External vs internal penetration testing: which do you need?

Use this as a starting point, and we confirm the right mix with you when we scope the work.

External testing

Choose it to learn who can get in

  • You have launched or changed internet-facing services
  • You have changed firewalls, VPN or remote access
  • A customer or auditor wants evidence about your perimeter
  • You want an independent check of what the internet can see
Internal testing

Choose it to learn how far they get

  • You want to know what a phished user could reach
  • You have redesigned the network or its zones
  • You hold card data and need PCI DSS segmentation testing
  • You are reviewing Active Directory or moving servers

Network penetration testing near you.

Our city pages cover the sectors, compliance needs and procurement routes that matter to buyers in each location, along with the local office contact details.

Checklist: preparing for a network penetration test.

Preparation makes the engagement faster and the results more useful.

  • Confirm the IP ranges, hostnames and sites in scope, and who owns each one.

  • Tell your hosting, cloud and managed service providers about the test window.

  • Name a technical contact who can answer questions while we test.

  • Agree any systems or times that are off limits.

  • For an internal test, prepare the device, account or network access we start from.

  • Make sure backups are current before testing starts.

  • Decide who will own the fixes and join the debrief.

What you receive after a network penetration test.

Each network test ends with a report your engineers can act on and your leaders can read. The full list of what every Vectra test includes is on our penetration testing services page.

  • Executive narrative

    A short report that explains the network risk in business terms for executives and boards.

  • Technical findings

    Each finding with the affected hosts, steps to reproduce it and the attack chain we used.

  • Ranked fix roadmap

    Remediation steps in order of risk, so your network team knows where to start.

  • Debrief and retest

    A walkthrough with your engineers, a retest of every High-severity finding and above, and 90 days of portal access to track fixes.

Compliance a network penetration test supports.

Our reports can be mapped to the frameworks you report against. Here is where a network test fits.

  • PCI DSS. Requirement 11.4 calls for external and internal penetration testing. Requirement 11.4.5 adds segmentation testing where you use segmentation to reduce scope. See our PCI DSS services.
  • ISO 27001. A network test gives evidence for technical vulnerability management and network security controls. See ISO 27001.
  • APRA CPS 234. Regulated entities must test their security controls. A network test is a common part of that program. See APRA CPS 234.
  • Essential Eight. Internal testing shows whether admin limits and patching hold up under attack. See the Essential Eight.
  • SOCI Act. Critical infrastructure entities can use test results as evidence for the cyber part of their risk management program. See the SOCI Act.

Related penetration tests.

Network testing often pairs with these tests.

Cloud penetration testing

Identity, storage and workloads in AWS, Azure and Google Cloud.

Wireless penetration testing

Wi-Fi sign-in, encryption and the walls between wireless and wired zones.

Web application penetration testing

The apps that sit on your network, tested against OWASP guidance.

Red and purple teaming

A goal-led attack that also tests how your team detects and responds.

Get a scoped network penetration testing quote.

Tell us your IP ranges, sites and goals. We scope each test to your environment and quote to that scope.

Network penetration testing FAQs.

What is the difference between external and internal penetration testing?

An external penetration test attacks your network from the internet, with no inside access, and shows whether an outsider can gain a foothold. An internal test starts from a foothold inside your network, such as a user account or a connected device, and shows how far an intruder could progress. Most organisations need both, because real attacks often chain an outside weakness to an inside one.

Do you need to be on site for an internal network pen test?

Not always. An internal penetration test needs a starting point inside your network, and we agree what that is when we scope the work. Some engagements are best run with a tester on site, and our testers are based in Australia and work nationally. External tests run over the internet, so they never need a site visit.

Will a network penetration test disrupt our systems?

We plan to avoid disruption. When we test production systems, we throttle our traffic, agree limits on risky actions in advance and keep a live bridge open to your team. Anything that could affect availability needs your approval first, and you choose the test windows, so sensitive work can run outside business hours.

What is the difference between network and infrastructure testing?

A network test looks at the services, devices and remote access an attacker can reach, and the paths between them. An infrastructure test goes deeper into servers, operating systems, identity, configuration, privilege and internal trust. The two often overlap, so we scope the combination that is most useful for your environment, and many tests cover both.

What do you need from us to scope a network test?

Tell us the IP ranges, domains and sites you want tested, and whether you need external, internal or both. Let us know which systems matter most, any times or systems that are off limits, and the reason for the test, such as PCI DSS or a customer request. With that information, we can scope the engagement and prepare a quote.

How often should we run external and internal pen tests?

Most organisations test at least once a year and again after significant network changes. PCI DSS asks for external and internal penetration testing at least every 12 months and after significant change. Segmentation tests may be needed more often for service providers. Your own risk, your customers and your regulators may set a higher bar.

Start with a conversation.

Speak to us about your cyber governance and compliance requirements.

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