BACKDOOR.WIN32.REMOTEMANIPULATOR / Insecure Permissions

[malvuln <malvuln13 () gmail com>]

Discovery / credits: malvuln - Malvuln.com (c) 2021
Original source:
http://malvuln.com/advisory/82183b3d85311a39fb80ae07357594e5.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: BACKDOOR.WIN32.REMOTEMANIPULATOR
Vulnerability: Insecure Permissions
Description: Creates a dir Folder139 with insecure permissions as it
hands authenticated users change permissions (C). The backdoor drops
an EXE named audiohd.exe which is not visible unless viewing using dir
/a command. There we find the exeuctable audiohd.exe and another
hidden DLL vp8encoder.dll

Type: PE32
MD5: 82183b3d85311a39fb80ae07357594e5
Vuln ID: MVID-2021-0005
Dropped files: audiohd.exe, vp8encoder.dll
Disclosure: 01/02/2021

Exploit/PoC:
C:\>cacls C:\Folder139
C:\Folder139 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:\Folder139>dir /a

02/15/2017  09:51 AM        1,486,848 audiohd.exe
07/15/2015  08:19 PM        607,440 vp8encoder.dll


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 occuring from improper
Malware handling or the downloading of ANY Malware mentioned on this
website or elsewhere. All content Copyright (c) Malvuln.com (TM).

_______________________________________________
Sent through the Full Disclosure mailing list
https://nmap.org/mailman/listinfo/fulldisclosure
Web Archives & RSS: http://seclists.org/fulldisclosure/