Lion Cipher Lab
Audit a Linux host with Lynis
- Cyber / Security Engineer
- Beginner
- ~30 min
- Free · no account required
Why it matters
You can't improve what you can't measure. Most people harden a box by following a checklist and hoping they didn't miss anything, with no way to tell how exposed the machine still is. A security auditing tool changes that: it inspects the running system against a large body of known good practice and hands you a concrete list of warnings and suggestions, plus a single hardening index score from 0 to 100 that captures the overall posture. Lynis does exactly this and is used widely for real system hardening and compliance checks. The skill that transfers to the job isn't memorizing findings —…
What you'll learn
- security auditing
- reading audit findings
- the hardening index
- acting on suggestions
- sysctl kernel hardening
- measuring before and after
Steps in this lab
- What a security audit tool actually does
- Install Lynis
- Run your first audit
- Read the warnings and suggestions
- Understand the hardening index score
- Act on a few real findings
- Re-run and watch the score move
- What you learned, and the habit underneath it