Trojan.Win32.Bayrob.dtrg / Insecure Permissions

[malvuln <malvuln13 () gmail com>]

Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source:
https://malvuln.com/advisory/2f3f0e9be7edb73e545fc49b5a78b4f0.txt
Contact: malvuln13 () gmail com
Media: twitter.com/malvuln

Threat: Trojan.Win32.Bayrob.dtrg
Vulnerability: Insecure Permissions
Description: Bayrob.dtrg creates an insecure dir named "mnfqzckna0dkc"
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: 2f3f0e9be7edb73e545fc49b5a78b4f0
Vuln ID: MVID-2021-0175
Dropped files: fuwa2hvojto7lyc1nnmuov.exe, k2fyqvt.exe, pnhky9c.exe,
stivbgcekgrl, oljlgxh, nxqdc3kf
Disclosure: 04/17/2021

Exploit/PoC:
C:\>cacls mnfqzckna0dkc
C:\mnfqzckna0dkc 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 mnfqzckna0dkc
 Volume in drive C has no label.

 Directory of C:\mnfqzckna0dkc

04/12/2021  08:27 PM           205,824 fuwa2hvojto7lyc1nnmuov.exe
04/12/2021  08:27 PM           205,824 k2fyqvt.exe
04/12/2021  08:27 PM                 0 nxqdc3kf
04/12/2021  08:28 PM                 4 oljlgxh
04/12/2021  08:27 PM           205,824 pnhky9c.exe
04/12/2021  08:27 PM                10 stivbgcekgrl
               6 File(s)        617,486 bytes


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