Use a payload (like a PHP reverse shell) to connect back to your listener ( nc -lvnp ).
The naming convention is where things get interesting. Why would a security challenge be named "hackfail"?
Run dig or nslookup . If a domain resolves to an IP outside your VPN range (like 127.0.0.1 or a public IP), you are in hackfail territory.
Inventory and reduce attack surface
The name of the machine is a hint. Often, the privilege escalation involves a or a script intended to fix a bug that actually introduces a new vulnerability. Look for custom scripts in /opt or /usr/local/bin that run with root privileges but have insecure file permissions. 5. Lessons Learned