You have been called to the office of the CEO for a confidential meeting. In the meeting the CEO informs you he 'has a virus that won't let him login without paying a fee.' You begin to investigate the issue and find that the CEO downloaded a file from a website a friend shared on a social media site. After downloading the file his computer restarted and now will not allow anyone to login unless they enter credit card information. Which option best describes the attack used in this scenario based on the information available?