Backdoor.Win32.NinjaSpy.c Code Execution

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/6eece319bc108576bd1f4a8364616264_B.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Backdoor.Win32.NinjaSpy.c  
Vulnerability: Remote Command Execution  
Description: The malware listens on TCP ports 2003, 2004 and drops a DLL named "cmd.dll" under Windows dir. Connecting to port 2003, you will get back a number "9951" from the infected host. If we send the value 1000 we get a message in Portugese "Pisca Pisca Ativado" translates to "Blink Blink Activated". If we connect to port 2004 and send "abc123" we get message "Acesso negado..." translates to "Access denied". However, if you take the initial number we received earlier (9951) when connecting to port 2003 and apply some calculation we expose hidden functionality. Take the 9951 value and invert the first two digits to 66 and then add together the last two 5 + 1 to equal 6 for a final value of "666". Example, initial number (9951) 99 inverted equals 66 and 5 + 1 = 6. Enter and send the constructed value of "666" to port 2003 and TCP port 999 is opened. Connect to port 999 and you get back a remote shell.  
Type: PE32  
MD5: 6eece319bc108576bd1f4a8364616264  
Vuln ID: MVID-2021-0202  
Dropped files: cmd.dll  
Disclosure: 05/04/2021  
  
Exploit/PoC:  
1) Enter "666" after the 9951, this opens port 999.  
  
nc64.exe 192.168.88.127 2003  
9951666  
  
  
2) Connect port 999  
  
nc64.exe 192.168.88.127 999  
C:\Users\Victim\Desktop>whoami  
whoami  
desktop-5c2jqhp\victim  
  
  
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).  
`