In most countries, hacking is a crime that is enforced at the national level. In the United States, for example, hacking attempts--successful or not--should be reported to the FBI. Be sure to take down as many details as possible, including name(s), email address (es), ransom amount(s), and emails or web pages that contained the malware.
Always be sure to document as much of the hacking incident as you can in order to provide law enforcement with as clear a picture as possible.