Tag Archive: ransomware


Disabling SMB v1 (lanmanserver “server service only”) on windows computers/servers:

 

a) for domain-based computers: use GPO “group policy object” to deploy the registry key to disable SMBv1 (server-side only) protocol on all systems (A reboot is required to take effect)

 

b) for isolated computer or non/domain joined computers: use the following command line to modify the lanmanserver registry key properly

 

Implementation – Technical details:

 

a) for domain-based computers, create a GPO or modify an existing GPO applied to computers only, to add the following registry key:

 

for domain-based computers, to create the GPO setting to disable SMB v1, use GPMC, Computer configuration, preferences, windows settings, registry, right-click, new registry item,

 

keep: Update,

Select the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters

 

Value: SMB1

Data: REG_DWORD 0

 

Note: To re-enable it

REG_DWORD: 1 = Enabled

Default: 1 = Enabled

 

 

b) for isolated computer or non/domain joined computers:

 

b.1) For Windows 8 and Windows server 2012 or greater (Note: not supported on Windows 7):

To obtain the current state of the SMB server protocol configuration, run the following cmdlet:

 

Get-SmbServerConfiguration | Select EnableSMB1Protocol

 

To disable SMBv1 on the SMB server, run the following cmdlet:

 

Set-SmbServerConfiguration -EnableSMB1Protocol $false

 

b.2) For Windows 7, Windows Server 2008 R2, Windows Vista, and Windows Server 2008

 

To enable or disable SMB protocols on an SMB Server that is running Windows 7, Windows Server 2008 R2, Windows Vista, or Windows Server

2008, use Windows PowerShell or Registry Editor.

 

To disable SMBv1 on the SMB server, run the following cmdlet:

 

Set-ItemProperty –Path “HKLM:\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters” SMB1 -Type DWORD -Value 0 –Force

 

To assess the impact:

 

This article contain a table to understand what version you will end up, depending on what Windows version is running as the SMB client and what version of Windows is running as the SMB server.

https://blogs.technet.microsoft.com/josebda/2012/06/06/windows-server-2012-which-version-of-the-smb-protocol-smb-1-0-smb-2-0-smb-2-1-or-smb-3-0-are-you-using-on-your-file-server/

 

http://www.lemondeinformatique.fr/actualites/lire-lexsi-trouve-un-vaccin-pour-stopper-la-propagation-de-locky-64309.html