Hack The Box is a massive, online cybersecurity training platform.

Here you can find my walkthroughs for all open & retired machines:

Difficulty: Easy
Technologies: Elasticsearch, Logstash
Vulnerabilities: Credentials in open database, log stash command as root
Walkthrough Scan for open ports: nmap -n …
Difficulty: Medium
Technologies: Apache, Postgres, Gitlab
Vulnerabilities: Web fuzzing, Credentials in data files, sudo permissions
Walkthrough Scan for open ports: nmap -n …