US CISA issues ICS ransomware factsheet.  Recommendations include:

Prepare:

• ID critical processes & equipment
• Develop and test response plan
• Ensure adequate backups in place

Mitigate:

• Practice cyber hygiene (patching, whitelisting, user management, MFA etc)
• Network segmentation
• Vigilent network monitoring

Respond:

• Isolate impacted systems
• Power down where  isolation is not possible
• Triage and restore impacted systems
• Obtain specialist third party assistance
• Take a forensic image
• Obtain decryptors via legal routes