Recently, someone discovered a kill switch for the ransomware.
There are rumours saying that the ransomware was spread via email phishing method. Most likely it spread remote execution using SMB vulnerability
Here is the simple check list can help reduce the risk from any variant of ransomware.
- Patch regularly and often.
- Disable SMBv1 on all systems.
- Ensure firewalls block SMB ports when not necessary.
- Isolate any systems that cannot be remediated to reduce impact.
All of these are basic steps you should take regardless of the threat. However, always disable unused services and protocols, always use a deny by default permit by exception policy on intersystem communication, and use network segmentation to reduce impact/risk.