Email-Worm.Win32.Trance.a / Insecure Permissions

[malvuln <malvuln13 () gmail com>]

Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source:
https://malvuln.com/advisory/ca18a07560efa0308827dc972351301f.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: Email-Worm.Win32.Trance.a
Vulnerability: Insecure Permissions
Description: The malware creates a dir named "DCA" and VBS file "log.vbs"
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: ca18a07560efa0308827dc972351301f
Vuln ID: MVID-2021-0261
Dropped files: log.vbs, zip.exe
Disclosure: 06/25/2021


Exploit/PoC:
C:\>cacls log.vbs
C:\log.vbs BUILTIN\Administrators:(ID)F
           NT AUTHORITY\SYSTEM:(ID)F
           BUILTIN\Users:(ID)R
           NT AUTHORITY\Authenticated Users:(ID)C


C:\>cacls DCA
C:\DCA 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 DCA
 Volume in drive C has no label.

 Directory of C:\DCA

06/16/2021  01:45 AM            67,072 zip.exe
               1 File(s)         67,072 bytes


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