Backdoor.Win32.Vernet.axt / Insecure Permissions

[malvuln <malvuln13 () gmail com>]

Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source:
https://malvuln.com/advisory/f529d60abbdafccce3dc5e5ffd6cdfa6.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Vernet.axt
Vulnerability: Insecure Permissions
Description: The malware writes an .EXE with insecure permissions under c:\
drive granting 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: f529d60abbdafccce3dc5e5ffd6cdfa6
Vuln ID: MVID-2021-0413
Disclosure: 12/03/2021


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


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

 Directory of C:\

06/17/2012  01:43 AM           146,944 chikean.exe
               1 File(s)        146,944 bytes


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