Backdoor.Win32.DarkKomet.artr / Insecure Permissions

[malvuln <malvuln13 () gmail com>]

Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source:
https://malvuln.com/advisory/d2ee6046fd47de321d1310dccacca92b.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.DarkKomet.artr
Vulnerability: Insecure Permissions
Description: The malware creates an hidden insecure dir named "Windupdt"
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: d2ee6046fd47de321d1310dccacca92b
Vuln ID: MVID-2021-0182
Dropped files: winupdate.exe
Disclosure: 04/21/2021


Exploit/PoC:
C:\>cacls Windupdt
C:\Windupdt 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 Windupdt
 Volume in drive C has no label.

 Directory of C:\Windupdt

               0 File(s)              0 bytes
               2 Dir(s)  34,641,420,288 bytes free


C:\>attrib -s -h Windupdt/*

C:\>dir Windupdt
 Volume in drive C has no label.

 Directory of C:\Windupdt

06/15/2012  05:07 PM           650,752 winupdate.exe
               1 File(s)        650,752 bytes





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