Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/d4ac133a9df0c627f899bb6039d04215.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Trojan.Win32.Agentb.iofv
Vulnerability: Insecure Permissions
Description: Agentb.iofv creates an insecure dir named "drivr" 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: d4ac133a9df0c627f899bb6039d04215
Vuln ID: MVID-2021-0172
Dropped files: hostloader.exe
Disclosure: 04/17/2021

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

 Directory of C:\drivr

06/14/2012  06:21 PM           293,376 hostloader.exe
               1 File(s)        293,376 bytes


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