45. Practice Exercises with Hints
45.8 Cloud, SOC, Hardening and Crypto – Mixed Drill
IAM least privilege, CloudTrail/GuardDuty awareness, fail2ban, firewalld, SSH keys, hashing vs encryption, TLS 1.2+.
| Exercise | Task | Hint |
|---|---|---|
| E1 | Write IAM policy idea: EC2 read-only S3 one bucket | Resource ARN scoped; no * on sensitive actions |
| E2 | Name three log sources a tiny SOC wants first | Auth logs, web access, CloudTrail / VPC flow (pick fit) |
| E3 | SSH hardening: PasswordAuthentication no – where? | sshd_config then sudo service sshd restart after test session |
| E4 | Why MD5 for passwords is wrong; name better | Rainbow / fast crack; use bcrypt/Argon2 |
| E5 | TLS: HTTP→HTTPS redirect checklist for Nginx | Listen 443 ssl; redirect 80; modern ciphers (defaults OK to start) |
| E6 | fail2ban: what does it ban and why Blue loves it | Repeated fails → jail IP; still need keys + SG |
| Red team (attacker) does | Blue team (defender) detects / stops |
|---|---|
| Uses stolen IAM key with AdminAccess | MFA; key age alerts; least privilege; GuardDuty-type findings |
| Brutes SSH; sprays passwords | Keys only; fail2ban; SG; monitoring /var/log/secure |
Ravindra Bagale's Tip
Students say "encryption" and "hashing" are the same. Interview: hash = one-way, for verification; encryption = two-way, to protect secrecy. Very simple – practise saying it out loud.
Ravindra Bagale's Tip – मराठी
Students "encryption" आणि "hashing" एकच म्हणतात. Interview: hash = one-way verify; encrypt = two-way, secrecy protect. एकदम simple – बोलून practice करा.
Ravindra Bagale's Tip – हिंदी
Students "encryption" और "hashing" को एक ही बताते हैं. Interview: hash = one-way verify; encrypt = two-way, secrecy protect. बिलकुल simple – बोलकर practice करो.
Lab
OWN Amazon Linux: enable key-only SSH in a new session before closing old one; install fail2ban (sudo yum install fail2ban where available) or document SG-only alternative; sudo service fail2ban start if installed. Notes: rollback plan.