Discovery / credits: Malvuln - malvuln.com (c) 2022
Original source: https://malvuln.com/advisory/1f84a5305b65d7f6aa3afa7e2f2bda0e.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Agent.baol
Vulnerability: Insecure Permissions
Description: The malware writes several PE files 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: 1f84a5305b65d7f6aa3afa7e2f2bda0e
Vuln ID: MVID-2022-0495
Disclosure: 02/21/2022


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


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

 Directory of C:\

02/11/2022  02:10 AM            70,411 NB_Server.exe
               1 File(s)         70,411 bytes
               0 Dir(s)  26,507,804,672 bytes free

C:\>cacls ds1.exe
C:\ds1.exe BUILTIN\Administrators:(ID)F
           NT AUTHORITY\SYSTEM:(ID)F
           BUILTIN\Users:(ID)R
           NT AUTHORITY\Authenticated Users:(ID)C

C:\>dir ds1.exe
 Volume in drive C has no label.

 Directory of C:\

02/11/2022  02:10 AM                 0 ds1.exe
               1 File(s)              0 bytes
               0 Dir(s)  26,506,407,936 bytes free



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