Infrastructure penetration testing, also called network penetration testing, is an authorized, scoped test of the servers, network devices, firewalls, and exposed services that make up your environment, from the public internet and from inside your network. A tester simulates the kinds of attacks a real adversary might attempt, validates weaknesses by hand, and confirms what could actually be reached within the rules agreed in scope. It produces a written report with validated findings, severity, evidence, and remediation guidance.
Short answer
An infrastructure penetration test is an authorized, scoped test of your networks, hosts, Active Directory, and network segments. It is the same service as network penetration testing. A tester works from the internet and from inside your network, confirms weaknesses by hand, and gives you a report with severity, evidence, and remediation guidance.
Why it matters
As attacker techniques change, regular testing helps you find and fix weaknesses before they are used against you. It gives you a clear, current picture of your exposure and reduces the risk of an incident, rather than leaving you to assume everything is fine.
What gets tested
Coverage is agreed in writing before testing begins, including the IP ranges, sites, and systems in scope and anything to exclude or handle carefully. Within that scope, an infrastructure test usually covers these areas:
- External-facing systems. Discovery of internet-facing systems and services, testing of exposed services for known and misconfigured weaknesses, review of authentication exposed to the internet, and validation of what an external attacker could actually reach.
- Internal networks. Testing from an assumed foothold inside the network, such as a connected device or a VPN account, to see how far an attacker could move and which high-value systems and data could be reached.
- Segmentation. Whether the separation between environments and sensitive systems holds in practice.
- Credential exposure and reuse. Whether credentials are exposed or reused in ways that open further access.
Infrastructure test methodology, phase by phase
An infrastructure test usually moves through the phases below, inside written authorization and agreed rules of engagement. Tool choice varies by engagement and is agreed by the testers. The names in the tools column are commonly used public tools, not a claim that The PenTesting Company uses any specific tool.
- 1
Reconnaissance and discovery
- 2
Vulnerability identification
- 3
Manual validation and exploitation
- 4
Internal movement and privilege paths
Only when in scope
- 5
Reporting and readout
| Phase | What the tester does | Commonly used, publicly available tools |
|---|---|---|
| Reconnaissance and discovery | The tester identifies live hosts and services in the agreed ranges. This can start from the public internet, from an agreed internal starting point, or both, depending on the written scope. | Nmap, masscan |
| Vulnerability identification | The tester reviews those services for known weaknesses and misconfigurations. Scanner output is a lead to check by hand, not a finding on its own. | Nessus, OpenVAS |
| Manual validation and exploitation within the rules of engagement | The tester confirms whether a weakness can actually be used, by hand, and only within the written authorization and rules of engagement. Work on a path typically stops once impact is confirmed, as agreed. | Metasploit, manual checks |
| Internal movement and privilege paths, only when in scope | When the scope allows internal testing, the tester may follow privilege paths and attempt lateral movement, including pivoting from a system already reached to other systems behind it that are not directly reachable. This stays inside the agreed rules of engagement. It is not part of an external-only test. | BloodHound, Responder, Impacket |
| Reporting and readout | Confirmed findings are written up with severity, evidence, business impact, and remediation guidance. The tester then walks the team through the report in a readout. | Written report and readout |
What an engagement looks like
Illustrative example, not a real client. The organization and details are hypothetical and are here to show the flow.
- Scope is agreed. The organization and the tester agree on a range of public IP addresses and one internal subnet, a testing window, any systems to exclude, and a named contact to reach right away if a critical-severity issue turns up.
- Discovery. Mapping the public range shows a management interface for a network device that is reachable from the internet and was not on the team's list of expected exposures.
- Manual validation. The tester checks the interface by hand rather than relying on scanner output, and confirms it uses a weak configuration. Testing stays within the agreed rules of engagement.
- Reporting. The finding is written up with a severity rating, the evidence of what was observed and how it was confirmed, the business impact, and a remediation step, such as limiting the interface to internal addresses and correcting the configuration.
- Readout and retest. The tester walks the team through the finding and helps them decide what to fix first. Retest terms set in the statement of work.
Example scope: an authorized infrastructure test
Illustrative only. Example Corp, example.com, and the address ranges below are placeholders, not a client. This shows what a written scope for one infrastructure test might cover.
- External in scope. The public range 192.0.2.0/24 and the hosts behind vpn.example.com and mail.example.com.
- Internal in scope. Testing from one laptop on the office user network 198.51.100.0/24, given to the tester as an agreed starting point.
- Active Directory. The corp.example.com domain, starting from one standard user account created for the test.
- Network segments. Whether the user network can reach the server network 203.0.113.0/24 and the payment segment that is meant to be isolated.
- Authorization. Written approval from Example Corp, plus written approval from the hosting provider that runs mail.example.com, since it controls that host.
- Rules of engagement. Agreed testing windows, no denial-of-service testing, no changes to production data, and a primary and backup contact who can pause testing and are told right away if we confirm a critical-severity issue.
- Out of scope. Staff personal devices, third-party systems not listed above, and social engineering.
Sample findings
Illustrative labels only, to show how findings are reported. They are not results from a real engagement.
| Severity | Illustrative finding | Where |
|---|---|---|
| Critical | Domain admin access reached from a standard user account through a chain of misconfigurations | Active Directory |
| High | Payment segment reachable from the office user network | Network segments |
| High | Network device management interface exposed to the internet | External |
| Medium | Shared local administrator password across workstations | Internal |
| Low | Outdated TLS settings on the VPN portal | External |
Deliverables
- A written report with each validated finding, its severity, evidence of how it was confirmed, business impact, and remediation guidance.
- A short summary for leadership.
- A readout to walk your team through the findings.
- Retest terms set in the statement of work.
An infrastructure penetration test is not a compliance certification.
Scope checklist
These questions help pin down what a test will cover. They do not prove the quality of any testing provider.
- Which public IP ranges and hostnames are in scope?
- Will the test include an internal starting point, and where on the network is it?
- Is Active Directory in scope, and from what starting account?
- Which network segments should be checked for separation?
- Who controls each asset, and has each of them authorized the test in writing?
- What are the testing windows, and which systems or techniques are excluded?
- Who is the named contact for a critical-severity issue, and who can pause testing?
- What does the report include, and how are retests handled?
Together, these assessments give you a practical view of your network security. You can read more on our network penetration testing page.
Frequently asked questions
Is infrastructure penetration testing the same as network penetration testing?
Yes. The two names describe the same service: an authorized, scoped test of your networks, hosts, Active Directory, and network segments, from outside and inside your environment.
What is the difference between an external and an internal test?
An external test starts from the public internet and looks at what an outside attacker could reach. An internal test starts from an agreed foothold inside the network, such as a connected laptop or VPN account, and looks at how far an attacker could move from there.
Who needs to authorize the test?
Whoever controls each asset in scope. That is usually your organization, plus any hosting provider, cloud provider, or managed service provider that runs systems in scope, if their terms require it. Authorization is agreed in writing before testing starts.
What happens if a critical-severity issue is found during testing?
We tell the named contact in your scope right away rather than waiting for the report, so your team can decide how to respond.
Will an infrastructure test make us compliant?
No. An infrastructure penetration test is not a compliance certification. The report can support a compliance program or a vendor review, but it does not make you compliant on its own.
What is pivoting in an infrastructure penetration test?
Pivoting means using a system the tester has already reached to test other systems behind it that are not directly reachable. It only happens when the scope allows internal testing, and it stays inside the agreed rules of engagement.
Have a system you want tested?
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