Discovery / credits: Malvuln - malvuln.com (c) 2021 Original source: https://malvuln.com/advisory/ed1e47f62fa93f2fd2f4fbcfdd0f1c10.txt Contact: malvuln13@gmail.com Media: twitter.com/malvuln Threat: Worm.Win32.Ngrbot.abpr Vulnerability: Insecure Permissions Description: Ngrbot.abpr creates a dir named "Win.Msi" under c:\ drive and grants change (C) permissions to the authenticated user group. Standard users can rename several of 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: ed1e47f62fa93f2fd2f4fbcfdd0f1c10 Vuln ID: MVID-2021-0142 Dropped files: alg.exe, cssrs.exe, System.exe, Disclosure: 03/24/2021 Exploit/PoC: C:\>cacls C:\Win.Msi C:\Win.Msi 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:\>cd Win.Msi C:\Win.Msi>dir Volume in drive C has no label. Directory of C:\Win.Msi 05/30/2008 12:25 PM 132 3proxy.cfg 12/06/2011 11:56 AM 184,832 alg.exe 12/06/2011 11:59 AM 315,392 cssrs.exe 10/17/2011 12:37 PM 494 DiskDoctor.lnk 04/17/2009 07:40 AM 330,752 System.exe 5 File(s) 831,602 bytes 0 Dir(s) 15,876,706,304 bytes free Disclaimer: The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. Do not attempt to download Malware samples. The author of this website takes no responsibility for any kind of damages occurring from improper Malware handling or the downloading of ANY Malware mentioned on this website or elsewhere. All content Copyright (c) Malvuln.com (TM).