Backdoor.Win32.VB.afu Insecure Permissions

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/c6ba7fcb9eb9bdd7e081e2e84e784dcb.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Backdoor.Win32.VB.afu  
Vulnerability: Insecure Permissions  
Description: The malware writes an .EXE with insecure permissions under c:\ drive granting change (C) permissions to the authenticated user group. Standard users can rename the executable dropped by the malware to disable it or replace it with their own executable. Then wait for a privileged user to logon to the infected machine to potentially escalate privileges.  
Type: PE32  
MD5: c6ba7fcb9eb9bdd7e081e2e84e784dcb  
Vuln ID: MVID-2021-0391  
Dropped files: Explorer.exe   
Disclosure: 11/05/2021  
  
  
Exploit/PoC:  
C:\>cacls Explorer.exe  
C:\Explorer.exe BUILTIN\Administrators:(ID)F  
NT AUTHORITY\SYSTEM:(ID)F  
BUILTIN\Users:(ID)R  
NT AUTHORITY\Authenticated Users:(ID)C  
  
  
C:\>dir /a \Explorer.exe  
Volume in drive C has no label.  
  
Directory of C:\  
  
06/16/2012 12:55 AM 222,195 Explorer.exe  
1 File(s) 222,195 bytes  
  
  
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