Trojan.Win32.VB.bcng Insecure Permissions

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/10550ca42c32c22bdd0515020cff38dd.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Trojan.Win32.VB.bcng  
Vulnerability: Insecure Permissions   
Description: The malware creates a dir with insecure permissions under c:\ drive and grants 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: 10550ca42c32c22bdd0515020cff38dd  
Vuln ID: MVID-2021-0272  
Dropped files: logs.exe, Trojan.Win32.VB.bcng.10550ca42c32c22bdd0515020cff38ddCMD.bat, Trojan.Win32.VB.bcng.10550ca42c32c22bdd0515020cff38ddMuC.bat  
Disclosure: 07/03/2021  
  
Exploit/PoC:  
C:\>cacls .exe  
C:\.exe BUILTIN\Administrators:(ID)F  
NT AUTHORITY\SYSTEM:(ID)F  
BUILTIN\Users:(ID)R  
NT AUTHORITY\Authenticated Users:(ID)C  
  
  
C:\>cacls Intel  
C:\Intel 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  
  
  
C:\>dir Intel\logs  
Volume in drive C has no label.  
  
Directory of C:\Intel\logs  
  
07/13/2012 02:52 AM 274,432 logs.exe  
1 File(s) 274,432 bytes  
3 Dir(s) 7,953,518,592 bytes free  
  
C:\>dir Intel\logs\Chip  
Volume in drive C has no label.  
  
Directory of C:\Intel\logs\Chip  
  
06/28/2021 03:29 AM 988 Trojan.Win32.VB.bcng.10550ca42c32c22bdd0515020cff38ddCMD.bat  
06/28/2021 03:29 AM 310 Trojan.Win32.VB.bcng.10550ca42c32c22bdd0515020cff38ddMuC.bat  
2 File(s) 1,298 bytes  
  
  
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