Apply the Microsoft security updates for MS17-010, including the updates for the Windows XP and Windows Server 2003 legacy operating systems. Disable SMBv1 on systems where it is not necessary (e.g. hosts that do not need to communicate with Windows XP and Windows 2000 systems). Carefully evaluate the need for allowing SMBv1-capable systems on interconnected networks compared to the associated risks. Scan networks for the presence of the DoublePulsar backdoor using plugins for tools such as Nmap. Use network auditing tools to scan networks for hosts that are vulnerable to the vulnerabilities described in MS17-010. Implement a backup strategy that includes storing data using offline backup media. Backups to locally connected, network-attached, or cloud-based storage are often insufficient because ransomware frequently accesses and encrypts files stored on these systems