IT Security Audit: What It Includes and How It Is Performed

1. Introduction

An IT security audit is the systematic process by which an organization evaluates the real state of its systems, networks, processes and people against cybersecurity risks. For a business owner or a CTO, an IT security audit is not an optional expense: it is the snapshot that allows you to justify investments, detect weaknesses before an attacker exploits them and demonstrate compliance to customers and regulators.

In this guide we explain what an IT security audit includes, how it is performed step by step, what deliverables it should produce and how much it costs. We will also look at how to tell a genuinely useful report from a simple document to file away, and which red flags you should watch when choosing a provider. If you need professional support, Jaymon Security helps companies plan and execute IT security audits with methodological rigour and a business focus.

2. What an IT security audit includes

There is no single picture of the IT security audit: its scope depends on the objective (regulatory, contractual or continuous improvement) and on the size of the organization. A company certified to ISO 27001 will need periodic internal audits; a public-sector entity will need the Spanish National Security Scheme (ENS) regime; a private company without regulatory obligations will mainly want to understand its risks and prioritize investments.

Regardless of the objective, every IT security audit combines three complementary layers: technical, process and governance. Leaving out any of them produces an incomplete picture that can give a false sense of security.

2.1. Technical IT security audit

The technical layer analyses digital assets: inventory of systems and services, server configuration, network segmentation, perimeter protection, access management and patching status. It includes tests such as vulnerability scanning, hardening reviews against CIS benchmarks and scoped, authorized penetration tests. This layer answers concrete questions: can an external attacker compromise my application? Do I have privileged accounts that nobody monitors? Do my backups really restore?

2.2. Process-oriented IT security audit

The process layer reviews policies, roles and responsibilities, change management, supplier management, incident management and business continuity. An exclusively technical audit usually discovers only the tip of the iceberg: process analysis identifies why those gaps exist and which organizational controls are failing. Findings in this layer usually have the greatest impact on the organization’s real maturity, because a perfect firewall does not prevent an accident caused by an untrained employee or an obsolete onboarding procedure.

3. Methodology and phases of the IT security audit

Every professional IT security audit follows a structured cycle, inspired by ISO 19011 and by good practice in information systems auditing. The phases adapt to the size of the company, but skipping any of them compromises the soundness of the result.

Scope and criteria: the limits of the IT security audit are fixed, together with the systems and processes included and the reference points (ISO 27001, ENS, CIS, OWASP, legal requirements).
Evidence gathering: interviews, document review, configurations, tool results and direct observation of the environment.
Analysis and cross-checking: evidence is compared against the criteria and findings are classified by severity and likelihood of materialization.
Report and action plan: executive and technical presentation, with prioritized recommendations, owners and deadlines.
Follow-up and retest: verification that the findings have been corrected within the agreed deadlines.

One of the first tasks of the IT security audit is to build or validate the asset inventory. Without an inventory, any subsequent analysis loses its foundation and findings cannot be prioritized correctly. A common format, also used by methodologies such as Magerit, is the following:

ASSET INVENTORY (extract)
-------------------------
[Dat] Customer database               Confidentiality: HIGH
[Sw]  ERP application                 Availability: HIGH
[Hw]  Production server               Dependencies: [Dat], [Sw]
[Com] Main Internet link              Value: 55.000 USD
[P]   Administration staff            Location: Madrid
[L]   Hosting provider datacentre     Access: contracted

Fig. 1 – Example of a Magerit-style asset inventory with preliminary valuation.

4. Common tools and tests

The IT security audit relies on widely proven tools, both commercial and open source. The most common ones in projects of this kind are:

Vulnerability scanning: Nessus, OpenVAS or Qualys against the internal network and Internet-facing services.
Configuration review: hardening checks of servers, databases and endpoints against CIS benchmarks.
Penetration testing: Nmap, Burp Suite or Metasploit, always with a previously signed scope and authorization.
Identity review: privileged accounts, inactive accounts, password policies and multi-factor authentication usage.
Backup review: verification of copies, encryption, retention and real restoration tests.

During the IT security audit, each test must be recorded with date, scope and person responsible. That traceability is the basis of the final report and avoids disputes over the results. For example, verifying the real configuration of a critical service produces evidence like this:

$ ssh -o BatchMode=yes admin@srv-prod 'systemctl status nginx'
● nginx.service - nginx web server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled)
   Active: active (running) since 2026-08-10 07:12:43 UTC

$ nmap -sV -p 22,443 10.0.0.5
PORT   STATE SERVICE VERSION
22/tcp open  ssh     OpenSSH 9.2 (protocol 2.0)
443/tcp open  https   nginx 1.24 (TLS 1.3 enabled)

Fig. 2 – Examples of technical checks during an IT security audit.

If the organization runs its own web applications, specific tests from the OWASP Top 10 are added: injection, broken access control, sensitive data exposure or session management. These tests require professional judgement so that operations are not interrupted, and they must always be performed in a controlled environment or with express authorization.

5. Deliverables and timelines of the audit

The result of the IT security audit is materialized in concrete, reviewable deliverables. The following table summarizes the typical phases of a project for an SME, with the deliverables and indicative duration of each one.

Phase	Deliverables	Indicative duration
Preparation	Scope document, schedule and reference criteria	1 week
Fieldwork	Asset inventory, interview checklist, test results	2-4 weeks
Analysis	Risk matrix and findings classified by criticality	1 week
Final report	Executive and technical report, prioritized remediation plan	1-2 weeks
Follow-up	Verification of corrections (retest) and project closure	2-4 weeks after fixes

A good IT security audit report separates the executive level (business impact, accepted or rejected risks, priorities) from the technical level (evidence, commands, specific configurations). If the report does not include prioritized recommendations with owners and deadlines, the IT security audit has not finished its job: it has produced a diagnosis without a treatment.

The results of the IT security audit should feed directly into the annual security plan: accept residual risks, transfer them through insurance or outsourcing, or treat them with concrete projects. A useful exercise is to classify each finding with two simple criteria — impact (high, medium, low) and remediation effort (high, medium, low) — and attack first what combines high impact with low effort. This matrix, which every professional report should include, turns findings into budget decisions and prevents the document from ending up on a shelf waiting for the next audit cycle. This is where the investment in the audit pays off: decisions based on evidence, not on opinions.

6. How much it costs and how to choose a provider

The cost of an IT security audit depends on the scope, the number of systems and the sector. As a reference, a medium-scope audit for an SME usually ranges between 3,000 and 12,000 euros; complete audits with extensive penetration testing for larger companies can exceed 25,000 euros. Excessively low prices usually hide generic reports or the absence of real testing.

When contracting an IT security audit, watch out for these red flags:

A fixed price without knowing the scope, the systems or the company’s sector.
A generic report with recommendations that seem copied from another client.
No technical evidence: logs, tool outputs or verified configurations.
Refusal to sign a non-disclosure agreement or to certify professional liability insurance.
Unrealistic deadlines or, on the contrary, open-ended schedules without verifiable milestones.
Lack of knowledge of the regulations applicable to your sector.

Before signing, the provider should answer five questions in writing: which methodology it will follow, who will perform the tests and with what certifications, which deliverables it will produce and in what format, how critical findings will be handled during the project, and what happens if an incident is detected in the middle of the audit. Written answers protect both parties and turn the negotiation into a transparent collaboration agreement.

Always ask for the methodology in writing and an example of a previous report. The IT security audit you hire must serve to make investment decisions, not just to tick a box. And demand a remediation plan: without it, the report is a list of problems you probably already suspected. A good contract should also include a cap on working days and a clear mechanism for resolving disputes about the scope of the tests.

7. Conclusion

The IT security audit is the most effective tool to understand the real state of your cybersecurity and prioritize investments with data, not with intuition. A well-executed audit produces a risk map, an organized remediation plan and a solid foundation for facing regulations such as the ENS or ISO 27001. Remember that the IT security audit does not end with the report: following up on the corrections is what really improves the company’s security posture, and the exercise should be repeated periodically to detect the drift that every organization suffers over time.

To go deeper into standards and good practices, consult the resources of ENISA, the documentation of ISO 27001 on iso.org and the guides of NIST.

If you want to apply all of this in your organization, Jaymon Security helps companies plan, execute and pass IT security audits with proven methodologies, actionable reports and business-oriented results.

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