First let's start with scanning the machine. There are a handful of possiblities to do this - Nmap, Rustscan, Angry IP Scanner, but I go with the classic - NMAP!
nmap -sC -sV <ip-address>
Starting Nmap 7.92 ( https://nmap.org ) at 2022-02-19 05:36 EST
Nmap scan report for 10.10.67.203
Host is up (0.21s latency).
Not shown: 997 closed tcp ports (conn-refused)
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 8.2p1 Ubuntu 4ubuntu0.3 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 3072 a3:6a:9c:b1:12:60:b2:72:13:09:84:cc:38:73:44:4f (RSA)
| 256 b9:3f:84:00:f4:d1:fd:c8:e7:8d:98:03:38:74:a1:4d (ECDSA)
|_ 256 d0:86:51:60:69:46:b2:e1:39:43:90:97:a6:af:96:93 (ED25519)
80/tcp open http Apache httpd 2.4.41 ((Ubuntu))
|_http-server-header: Apache/2.4.41 (Ubuntu)
|_http-title: Apache2 Ubuntu Default Page: It works
445/tcp open http Apache httpd 2.4.41 ((Ubuntu))
|_http-server-header: Apache/2.4.41 (Ubuntu)
|_http-title: Apache2 Ubuntu Default Page: It works
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Host script results:
|_smb2-time: Protocol negotiation failed (SMB2)
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 61.86 seconds
Directory discovery
AKA, directory enumeration - Think about the author's tip!
Let's launch our tool...
gobuster dir -u http://<ip-address>/ -w /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt
===============================================================
Gobuster v3.1.0
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url: http://10.10.67.203/
[+] Method: GET
[+] Threads: 10
[+] Wordlist: /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt
[+] Negative Status codes: 404
[+] User Agent: gobuster/3.1.0
[+] Timeout: 10s
===============================================================
2022/02/19 05:36:58 Starting gobuster in directory enumeration mode
===============================================================
/axxxx (Status: 301) [Size: 312] [--> http://<ip-address>/axxxx/]
/sxxxxx (Status: 200) [Size: 25]
/pxxxxx (Status: 200) [Size: 25]
There is a handful of things that can be found first, but are any of them real?
These three directories are a trap, it seems the author likes base64...
/axxxx holds a file named id_rsa, but it's too small to hold an actual id_rsa key!