Silo focuses mainly on leveraging Oracle to obtain a shell and escalate privileges. It was intended to be completed manually using various tools, however Oracle Database Attack Tool greatly simplifies the process, reducing the difficulty of the machine substantially.

Grandpa is one of the simpler machines on Hack The Box, however it covers the widely-exploited CVE-2017-7269. This vulnerability is trivial to exploit and granted immediate access to thousands of IIS servers around the globe when it became public knowledge.

Granny, while similar to Grandpa, can be exploited using several different methods. The intended method of solving this machine is the widely-known Webdav upload vulnerability.

Devel, while relatively simple, demonstrates the security risks associated with some default program configurations. It is a beginner-level machine which can be completed using publicly available exploits.