Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/304fb160949dcaec3e718481464f9ce6.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln
Threat: Trojan.Win32.Banpak.kh
Vulnerability: Insecure Permissions
Description: The malware creates a dir 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: 304fb160949dcaec3e718481464f9ce6
Vuln ID: MVID-2021-0258
Dropped files: taskhostoy.exe, vp8encoder.dll
Disclosure: 06/23/2021
Exploit/PoC:
C:\>cacls ZpaTo68.tmp
C:\ZpaTo68.tmp 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 ZpaTo68.tmp
Volume in drive C has no label.
Directory of C:\ZpaTo68.tmp
10/10/2017 04:44 AM 4,570,112 taskhostoy.exe
06/17/2021 2:33 AM 1,639,336 vp8encoder.dll
2 File(s) 6,209,448 bytes
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