A first nmap scan indicates that the box could be a Windows DC:
sudo nmap -p- <IP>
PORT STATE SERVICE VERSION
135/tcp open msrpc Microsoft Windows RPC
139/tcp open netbios-ssn Microsoft Windows netbios-ssn
445/tcp open microsoft-ds Windows 7 Professional 7601 Service Pack 1 microsoft-ds (workgroup: WORKGROUP)
49152/tcp open msrpc Microsoft Windows RPC
49153/tcp open msrpc Microsoft Windows RPC
49154/tcp open msrpc Microsoft Windows RPC
49155/tcp open msrpc Microsoft Windows RPC
49156/tcp open msrpc Microsoft Windows RPC
49157/tcp open msrpc Microsoft Windows RPC
nmap scanning with basic scripts reveals a possibly vulnerable smb server:
sudo nmap -sC <IP>
Host script results:
| smb2-security-mode:
| 2.1:
|_ Message signing enabled but not required
| smb-security-mode:
| account_used: guest
| authentication_level: user
| challenge_response: supported
|_ message_signing: disabled (dangerous, but default)
| smb2-time:
| date: 2021-10-04T18:49:13
|_ start_date: 2021-10-04T18:47:36
| smb-os-discovery:
| OS: Windows 7 Professional 7601 Service Pack 1 (Windows 7 Professional 6.1)
| OS CPE: cpe:/o:microsoft:windows_7::sp1:professional
| Computer name: haris-PC
| NetBIOS computer name: HARIS-PC\x00
| Workgroup: WORKGROUP\x00
|_ System time: 2021-10-04T19:49:12+01:00
|_clock-skew: mean: -18m27s, deviation: 34m36s, median: 1m30s
<SNIP>
This in combination with the box being called "Blue" screams for the Eternal Blue / Eternal Romance SMB exploit and indeed:
Host script results:
| smb-vuln-ms17-010:
| VULNERABLE:
| Remote Code Execution vulnerability in Microsoft SMBv1 servers (ms17-010)
| State: VULNERABLE
| IDs: CVE:CVE-2017-0143
| Risk factor: HIGH
| A critical remote code execution vulnerability exists in Microsoft SMBv1
| servers (ms17-010).
|
| Disclosure date: 2017-03-14
| References:
| https://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/
| https://technet.microsoft.com/en-us/library/security/ms17-010.aspx
|_ https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-0143
Eternal Blue RCE
It's a kernel exploit and I didn't take the time to write my own PoC. Shame on me. But the according metasploit module returned a shell and so I finished the box. Of course there are also PoC scripts available online if you do not want to use metasploit.