Penetration Testing services

Even the most sophisticated security programs need to be challenged. Penetration testing gives you clarity and control by showing you exactly where your vulnerabilities are.

We approach your systems just like an attacker would - testing not just your tech, but your people and processes too. It’s a safe, structured way to get honest answers about where you’re strong and how to improve.

With this knowledge, you can prioritise remediation, justify investment, and demonstrate risk control to your board, regulators, and customers. It also strengthens compliance with frameworks like ISO 27001 and PCI DSS, helping you prove that you’re not just ticking boxes.

At Nasstar, our penetration testing services combine CREST-accredited testers, proven methodologies, and clear reporting. Whether you need a one-off penetration test, a recurring pen testing programme, or fully managed penetration testing as a service (PTaaS), we shape the engagement around your environment, your compliance obligations, and the threats most relevant to your sector.

Penetration testing services, often called pen testing services, pentesting services, or simply a pen test, are ethical hacking engagements where qualified testers attempt to find and exploit vulnerabilities in your systems in a controlled, safe way. The goal is simple: surface the security weaknesses a real attacker would find, before they do.

1. Scope and plan

We start with a scoping conversation to understand your environment, goals, risk appetite, and any compliance drivers (ISO 27001, PCI DSS, NIS2). We agree on the test type, methodology, rules of engagement, timing, and reporting requirements before any testing begins.

2. Reconnaissance and discovery

Our pen testers carry out targeted reconnaissance of the in-scope environment, mapping the attack surface, identifying technologies and services, and surfacing potential entry points. This stage replicates what a real attacker would do before engaging.

3. Test and exploit

This is the active penetration testing phase. Testers attempt to exploit identified weaknesses, chain vulnerabilities together, escalate privileges, and move laterally, all within the agreed scope and rules of engagement. Everything is logged for the final report.

4. Report and debrief

You receive a written penetration testing report with an executive summary, a prioritised findings list (ranked by business impact, not just CVSS score), evidence for each finding, and clear remediation guidance. We follow up with a debrief call so your team can ask questions.

5. Remediate and retest

Once your team has remediated the findings, we run a retest to confirm the fixes are effective. For organisations on a continuous programme, for example, through penetration testing as a service, retests roll into the next testing cycle automatically.