What is a security audit and how to prepare for one

· Category: Cybersecurity

Short answer

A security audit is an independent review of your organization's security controls, policies, and infrastructure. Auditors verify that security measures match stated policies and industry standards (SOC 2, ISO 27001, GDPR). Preparation involves documenting policies, evidence of controls, access logs, and incident response procedures. For compliance requirements, see how to achieve GDPR compliance.

What auditors examine

  1. Access controls: Who has access to what? Is least privilege enforced? See authentication vs authorization for the basics
  2. Data protection: Encryption at rest and in transit, key management
  3. Network security: Firewalls, segmentation, monitoring
  4. Incident response: Do you have a plan? When was it last tested?
  5. Change management: How are changes to production reviewed and approved?
  6. Logging and monitoring: Are security events logged? How long are logs retained?

How to prepare

  • Document everything: Policies, procedures, and evidence that controls exist
  • Run a pre-audit: Use checklists based on your target framework (SOC 2 TSC, ISO 27001 Annex A)
  • Fix known gaps: Resolve findings from vulnerability scans before auditors find them
  • Train your team: Everyone should know the security policies that apply to their role
  • Organize evidence: Create a folder per control with screenshots, configs, and logs

Tips

  • Start preparing at least 3 months before the audit window
  • Internal audits should happen quarterly; external audits annually
  • Automate evidence collection where possible (cloud audit logs, access reviews)