Trojan.Win32.NanoBot.onh Insecure Permissions

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/9fff4c02274c0162880844f27ff91407.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Trojan.Win32.NanoBot.onh  
Vulnerability: Insecure Permissions  
Description: NanoBot.onh creates an insecure dir named "AppData" 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. In this case the dropped file "amsiproxy.bat" is actually an PE32 executable as indicated by the presence of MZ header field and binary data.  
Type: PE32  
MD5: 9fff4c02274c0162880844f27ff91407  
Vuln ID: MVID-2021-0173  
Dropped files: amsiproxy.bat (PE32)  
Disclosure: 04/17/2021  
  
Exploit/PoC:  
C:\>cacls AppData  
C:\AppData 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:\AppData\Register-CimProvider>dir  
Volume in drive C has no label.  
  
Directory of C:\AppData\Register-CimProvider  
  
04/15/2021 10:50 PM 1,101,316 amsiproxy.bat  
1 File(s) 1,101,316 bytes  
  
  
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