Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/8df7527bd3446b89298c9c750394e0b6.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Worm.Win32.Detnat.c
Vulnerability: Insecure Permissions
Description: Detnat.c creates a dir named "Recycled" under c:\ drive and grants change (C) permissions to the authenticated user group. Standard users can rename the "svch0st.exe" 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: 8df7527bd3446b89298c9c750394e0b6
Vuln ID: MVID-2021-0139
Dropped files: svch0st.exe
Disclosure: 03/23/2021

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

 Directory of C:\Recycled

06/14/2012  06:15 PM         61,088 svch0st.exe


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