What a Security Audit Involves, Step by Step

A security audit is a structured review of how well your people, processes and technology protect your information. It starts by agreeing scope, then collects evidence (documents, interviews, configuration and technical checks), compares what it finds against a reference such as your own policies or a recognised framework, and ends with a prioritised report of risks and recommended fixes. A good audit tells you what is exposed, how serious it is, and what to do first. Here is what each stage involves and how to get value from it.

Audit, assessment, penetration test: what is the difference?

These terms are used loosely, so confirm what you are buying.

Activity	What it does	Typical question answered
Security audit	Reviews controls, configuration and evidence against a standard or policy	Are we doing what we say we do, and is it enough?
Risk assessment	Identifies assets, threats and likelihood and impact	What matters most and what could go wrong?
Vulnerability scan	Automated search for known weaknesses in systems	Which known flaws exist right now?
Penetration test	Skilled testers attempt to exploit weaknesses safely	What could a determined attacker actually achieve?

A thorough engagement often combines several of these.

Stage 1: scope and objectives

Decide what is being examined and why. Is it the whole company, one web application, the office network, or cloud accounts? Is the driver a customer questionnaire, an insurance renewal, a data protection concern or simply good practice? Agree the boundaries, the people involved, the timeline and the rules, including what must not be touched. A vague scope produces a vague report.

Stage 2: information gathering

The reviewer collects your inventory of systems and data, network diagrams, policies, supplier list, previous incident notes and organisational structure. Missing documentation is itself a finding, because it shows where knowledge sits only in someone's head.

Stage 3: review of controls

This is the core of the audit. Typical areas include:

• Identity and access: who has accounts, whether MFA is enforced, how admin rights are granted and removed, and how leavers are handled.
• Devices and endpoints: patching, disk encryption, endpoint protection and mobile device management.
• Network and perimeter: firewall rules, remote access, exposed services, segmentation and Wi-Fi configuration.
• Cloud and email: tenant settings, sharing permissions, mail authentication and logging.
• Data protection: where personal and sensitive data lives, encryption at rest and in transit, retention and backup.
• Applications: secure development practices, dependency management and access controls in your own software.
• Monitoring and response: logging, alerting, incident procedures and whether anyone would notice a breach.
• Suppliers: how third parties access or hold your data.
• People and policy: awareness training, acceptable use and onboarding and offboarding.

Stage 4: technical checks

Where the scope includes it, the reviewer will run scans and inspect configurations. Examples: checking for missing patches, expired or weak certificates, open ports, default credentials, over-permissive storage and insecure settings. Intrusive testing should only happen with written authorisation, agreed windows and a clear escalation contact.

Stage 5: analysis and rating

Findings are rated by risk, which combines how easy something is to exploit with how bad the consequences would be. Sensible reports explain the reasoning rather than just showing red, amber and green. One critical issue on an internet-facing system matters more than twenty low-risk items on an isolated machine.

Stage 6: the report and the read-out

A useful report has an executive summary in plain language, a list of findings with evidence, a risk rating, a recommended fix and a suggested owner, and a prioritised action plan. Ask for a walkthrough meeting, because discussion often surfaces context that changes the priorities.

Stage 7: remediation and re-check

Fixes rarely arrive all at once, so sequence them. Quick wins such as enabling MFA, removing unused accounts and closing exposed ports can often be done within days, while structural changes such as redesigning network segments need planning and budget.

The audit only pays off when findings are fixed. Turn the report into a tracked plan with owners and dates, tackle the high-risk items first, and schedule a re-check to confirm fixes worked. Some items will be accepted as residual risk; record who accepted them and why.

How to prepare

1. Appoint one internal contact with authority to grant access and answer questions.
2. Gather your system and supplier lists, policies and recent changes.
3. Make sure you actually own or control what is in scope, and obtain permission from third parties for any testing of their platforms.
4. Tell staff the audit is happening and that interviews are about systems and processes, not blame.
5. Agree how sensitive findings and evidence will be stored and who can see the report.
6. Back up critical systems before any active testing.

Choosing who performs the audit

You can use internal staff, an external specialist, or both. Internal reviewers know your systems but may have blind spots and conflicts of interest, since they are checking their own work. External reviewers bring fresh eyes and wider experience but need time to learn your context. Whoever does it, ask for a written scope, a sample report structure, a statement of how they handle your data, and confirmation of the methods they will use. Be cautious of anyone who promises that you will "pass" or guarantees a particular result before they have looked at anything. Ask what happens to the evidence afterwards, how long it is retained, and who within their team will see it. Clarify whether the engagement includes help with fixes or only reports on them, as these are often separate pieces of work.

Common mistakes

• Auditing to tick a box. A report that sits in a drawer changes nothing. Plan the fixes up front.
• Scope that is too wide or too narrow. Too wide dilutes depth; too narrow misses the system attackers actually reach.
• Cleaning up just before the auditor arrives. You get a flattering snapshot of an unrealistic state.
• Confusing a scan with an audit. A scanner output is a data source, not an assessment.
• No owner for findings. Each issue needs a named person and a date.
• Treating compliance as security. Meeting a checklist is not the same as being protected against realistic attacks.

Audit and data protection

Because GDPR expects organisations to test and evaluate the effectiveness of their technical and organisational measures regularly, audits are a natural way to show you take this seriously. It is not a legal requirement to use any particular format. See our article on GDPR and security; this is general information and not legal advice.

Internal checks you can do first

You can reduce the cost and improve the value of an external audit by doing a lightweight self-assessment first. Use our cybersecurity checklist as a starting point, fix the obvious gaps, and keep the evidence: screenshots of settings, lists of users, dates of backup tests. Evidence turns statements like "we enforce MFA" into something an auditor can verify, and it speeds up the work considerably.

Next steps

If you want an independent view of your security posture, agree scope and goals first, then work from the findings in priority order. Our cybersecurity solutions include security audits alongside encryption, authentication and threat monitoring, and we are happy to discuss what an audit of your environment would cover.