OTOMY
SOC/SIEMJuly 11, 20266 min

Free Internal Cybersecurity Audit for SMBs: Complete 2024 Guide

80% of SMBs never audit their IT security until it's too late, and the breach becomes the wake-up call. Here's how to run a complete, free internal cybersecurity audit in less than a day.

M

By

Melissa Slimani

Free Internal Cybersecurity Audit for SMBs: Complete 2024 Guide

Why an internal cybersecurity audit is urgent for your SMB

SMBs now represent 43% of targeted cyberattacks, yet fewer than 15% have ever conducted a formal security audit. The common excuse? People assume audits are expensive and require external consultants. That's false. With the right tools and a clear methodology, you can run a solid internal audit without spending a single euro.

At Otomy, we support SMBs across France and Algeria on their IT infrastructure, and an internal audit is always the first step before deploying a SOC/SIEM setup or a full DevSecOps strategy.

Step 1: Map your attack surface

Before any audit, you need to know exactly what you're protecting.

  • Asset inventory: servers, workstations, network printers, IoT devices, cloud accounts (Microsoft 365, Google Workspace)
  • Access inventory: who has access to what? VPN, RDP, admin rights
  • Network mapping: use free tools like Nmap or Angry IP Scanner to scan your local network and detect unauthorized devices
# Basic network scan with Nmap
nmap -sV -O 192.168.1.0/24

This scan reveals active services, outdated software versions, and unnecessarily open ports — often the first entry point for attackers.

Step 2: Audit passwords and authentication

This is the #1 weak point for SMBs. Check for:

  • Multi-factor authentication (MFA) on all critical accounts (email, cloud, VPN)
  • Use of a password manager (Bitwarden's free tier is excellent for teams)
  • Default passwords still active on routers, printers, or IP cameras

Recommended free tool: Have I Been Pwned for Business lets you check if emails from your domain have leaked in known data breaches.

Step 3: Check updates and patches

A quick audit of your systems should include:

  • Pending Windows Update / security patches
  • CMS versions (WordPress, Prestashop) and associated plugins
  • Firmware on network equipment (routers, firewalls)

Use OSSEC or Wazuh (open source, free) to centralize endpoint monitoring — a solid foundation before moving to a full SIEM.

Step 4: Test your backup resilience

A cybersecurity audit without a restoration test is worthless. Ask yourself:

  • Are your backups isolated from the main network (3-2-1 rule)?
  • Have you tested a full restoration in the last 6 months?
  • Are your cloud backups (Google Drive, OneDrive) protected against ransomware through versioning?

Step 5: Analyze logs and automate detection

This is where a basic audit becomes a real lightweight SOC/SIEM setup. With no-code tools like n8n, you can:

  • Automate log collection from your firewalls and servers
  • Create Slack or email alerts for suspicious logins (new IP, brute-force attempts)
  • Connect Wazuh to an n8n workflow to automatically triage critical alerts
// Example n8n webhook for security alert
{
  "trigger": "failed_login_attempt",
  "threshold": 5,
  "action": "send_slack_alert",
  "channel": "#security-alerts"
}

Step 6: Train your team (the weakest link)

90% of security incidents involve human error. Run a free internal phishing test with GoPhish (open source) to measure your employees' click rate on fake malicious emails.

Final checklist for your free audit

  • Complete IT asset inventory
  • Network scan with Nmap
  • MFA enabled on all critical accounts
  • Data breach check (Have I Been Pwned)
  • Patches and updates current
  • Backup restoration test
  • Wazuh deployed for monitoring
  • Phishing test with GoPhish
  • Alert automation via n8n

What comes after the audit?

A free internal audit typically reveals 10 to 20 critical vulnerabilities in a standard SMB. The next step is prioritizing fixes based on risk, then considering a managed SOC/SIEM solution for continuous 24/7 monitoring.

At Otomy, we help French and Algerian SMBs turn this initial audit into a sustainable cybersecurity strategy, fully integrated with their IT infrastructure and business automation tools.

Want to go further? Contact our team for an in-depth audit and a tailored action plan.

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