Machine Synopsis

Undetected is a medium Linux machine that features an Apache server on `port 80`, which serves a jewellery store website. The initial foothold is gained by exploiting a PHP command injection vulnerability present in the web application to gain a `www-data` user shell. Enumeration shows that the system had been previously compromised and privilege escalation requires retracing the attacker's steps in order to find the backdoors that were left behind by the initial compromise. We are further required to analyse and reverse engineer the backdoor inside the `sshd` binary, which leads to a full system access as the `root` user.