Ransomware Builder Babuk Insecure Permissions

`Discovery / credits: Malvuln - malvuln.com (c) 2022  
Original source: https://malvuln.com/advisory/5dfa998f62612e10d5d28d26948dd50f.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Ransomware Builder Babuk  
Vulnerability: Insecure Permissions  
Description: The malware creates directorys with insecure permissions when write to 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: 5dfa998f62612e10d5d28d26948dd50f  
Vuln ID: MVID-2022-0461  
Disclosure: 01/19/2022  
  
  
Exploit/PoC:  
C:\>builder.exe  
Usage: builder.exe FolderName  
  
C:\>builder.exe c:\hate  
Creating folder 'c:\hate'  
curve25519 keys generated.  
"c:\hate\e_win.exe" written!  
"c:\hate\d_win.exe" written!  
"c:\hate\e_esxi.out" written!  
"c:\hate\d_esxi.out" written!  
"c:\hate\e_nas_x86.out" written!  
"c:\hate\d_nas_x86.out" written!  
"c:\hate\e_nas_arm.out" written!  
"c:\hate\d_nas_arm.out" written!  
"c:\hate\kp.curve25519" written!  
"c:\hate\ks.curve25519" written!  
Press any key to continue . . .  
  
C:\>cacls \hate  
C:\hate BUILTIN\Administrators:(OI)(CI)(ID)F  
NT AUTHORITY\SYSTEM:(OI)(CI)(ID)F  
BUILTIN\Users:(OI)(CI)(ID)R  
NT AUTHORITY\Authenticated Users:(ID)C  
NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C  
  
  
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