Worm.Win32.Delf.hu Insecure Permissions

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/46e27d7bfdbda7a71dfa12a79026a88b.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Worm.Win32.Delf.hu  
Vulnerability: Insecure Permissions  
Description: The malware creates a hidden insecure dir named "RECYCLER" under c:\ drive and grants change (C) permissions to the authenticated user group. Standard users can rename the executables 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: 46e27d7bfdbda7a71dfa12a79026a88b  
Vuln ID: MVID-2021-0192  
Dropped ok.exe, REM.com  
Disclosure: 04/29/2021  
  
Exploit/PoC:  
C:\>dir /a RECYCLER  
Volume in drive C has no label.  
  
Directory of C:\RECYCLER  
  
06/16/2012 12:21 AM 449,024 ok.exe  
06/16/2012 09:55 AM 61,952 REM.com  
2 File(s) 510,976 bytes  
2 Dir(s) 23,871,930,368 bytes free  
  
C:\>cacls RECYCLER  
C:\RECYCLER 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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