Backdoor.Win32.Cyn.20 malware suffers from an insecure permissions vulnerability.
ec8928cddb99ad4862c9cdb1505fc61dDiscovery / credits: Malvuln - malvuln.com (c) 2022
Original source: https://malvuln.com/advisory/3dd1da64e306cae0409e154e15dd1b80.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: Backdoor.Win32.Cyn.20
Vulnerability: Insecure Permissions
Description: The malware writes a ".EXE" file with insecure permissions to 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.
Family: Cyn
Type: PE32
MD5: 3dd1da64e306cae0409e154e15dd1b80
Vuln ID: MVID-2022-0524
Disclosure: 03/25/2022
Exploit/PoC:
C:\>cacls "Program Filessystem.EXE"
C:\Program Filessystem.EXE BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
C:\>dir "Program Filessystem.EXE"
Volume in drive C has no label.
Directory of C:\
03/22/2022 02:35 AM 0 Program Filessystem.EXE
1 File(s) 0 bytes
0 Dir(s) 24,893,874,176 bytes free
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