This machine is very straight forward based on public exploit.

Focus on Enumeration, This box is quite easy one !

This machine is based on command injection some parameter mining or bruteforce.

This machine teaches about the race conditions along with symlinks.

This machine is based on sqli

AD Machine with SeBackupPrivilege Enabled

Proving Ground Practice Hard Level Machine ! You mainly gona learn about Cryptography and Padding Oracle Attack.

SQL Injection, Weak Credentials, Misconfiguration, Insecure Design, RCE, Arbitrary File Upload, Arbitrary File Read, Clear Text Credentials

Proving Ground Practice Easy Level Machine !

Proving Ground Practice Easy Level Machine ! you gona learn about Squid Connections and RFI.