What can i do?

Apply the patch Microsoft released in March that fixes this issue MS17-010. (https://technet.microsoft.com/en-us/library/security/ms17-010.aspx) You should also make sure you firewall is properly configured to block SMB and RDP access to the internet. Finally you should disable SMBv1.(https://support.microsoft.com/en-us/help/2696547/how-to-enable-and-disable-smbv1,-smbv2,-and-smbv3-in-windows-vista,-windows-server-2008,-windows-7,-windows-server-2008-r2,-windows-8,-and-windows-server-2012) Please be aware disabling SMBv1 on XP and 2003 machines and older will likely break file sharing.