Oklahoma state officials, Office of Management and Enterprise Services suffered from a ransomware incident in February 2017.
Data was encrypted and locked by hackers, who demanded a ransom; however, the corporation refused to pay.
Source: https://www.databreaches.net/oklahoma-gov-omes-confirm-unnamed-agency-hacked-no-ransom-paid/
"id": "OFF0485722",
"linkid": "oklahomaomes",
"type": "Ransomware",
"date": "02/2017",
"severity": "100",
"impact": "5",
"explanation": "Attack threatening the organization’s existence"