# Hash a file and verify it
sha256sum report.pdf > report.sha256
sha256sum -c report.sha256

# Inspect a website's TLS certificate
openssl s_client -connect example.com:443 -servername example.com </dev/null 2>/dev/null \
  | openssl x509 -noout -subject -issuer -dates

# Who can read this file?
ls -l /etc/shadow
# -rw-r----- 1 root shadow ... → only root and the shadow group

# Find world-writable files in a lab directory (a common weakness)
find /opt/lab -type f -perm -o+w 2>/dev/null

# Fix one
chmod o-w /opt/lab/config.ini

# INSECURE: user input joined into SQL (lab demonstration only)
query = f"SELECT * FROM users WHERE name = '{name}'"

# SECURE: parameterised query
import sqlite3
con = sqlite3.connect("lab.db")
rows = con.execute("SELECT * FROM users WHERE name = ?", (name,)).fetchall()
# The course teaches both: how the flaw works, and how to fix it

Finding
Title: Reflected XSS in search parameter (lab app)
Severity: Medium
Location: /search?q=
Evidence: script in the q parameter executed in the browser
Impact: attacker could run scripts in a victim's session
Recommendation: encode output, validate input, set Content-Security-Policy
Reference: OWASP Top 10 — Injection

# Find repeated failed SSH logins in a sample auth log
grep "Failed password" sample_auth.log \
  | awk '{print $(NF-3)}' | sort | uniq -c | sort -rn | head -5

# Check whether any of those IPs later logged in successfully
grep "Accepted password" sample_auth.log | awk '{print $(NF-3)}' | sort -u

Final project (typical structure)
Scenario: a small company's lab network and web app
1. Map assets and network
2. Assess the web app and servers (in scope only)
3. Report findings with severity and fixes
4. Apply hardening to two systems
5. Set up basic log monitoring and one alert
6. Run a short incident response simulation
7. Present to a non-technical 'management' audience

Module Tracker
Module                       Classes   Labs   Notes written   Confidence (1-5)
Networking                   __/__     __     ☐               ___
Linux and Windows            __/__     __     ☐               ___
Security concepts            __/__     __     ☐               ___
Cryptography                 __/__     __     ☐               ___
Web application security     __/__     __     ☐               ___
Network scanning             __/__     __     ☐               ___
Hardening                    __/__     __     ☐               ___
Monitoring and SIEM          __/__     __     ☐               ___
Incident response            __/__     __     ☐               ___

Lab Log
Date: ______  Module: ______
Lab target: ______ (lab only)
Goal: ______________
Commands/tools used: ______________
What I found: ______________
How it could be fixed: ______________
Write-up done? ☐

Questions for the counsellor
1. Can I see the current module list with hours?
2. How many lab hours per week?
3. Which tools and lab environments are used?
4. What does the final project include?
5. Which batches are available, and what is the current fee?