@Bluewall And here is where academics and the real world differ. Does a DDOS impact the availability of the data - yes but only thru the one service being targeted. If this is a multiple choice test - the correct one is ransomware as that directly targets the availability of data no matter which service is trying to use it. Think of it this way, a DDOS (of Service) could lock up your web server so that clients couldn't authenticate, get to their data. But an engineer on the back end could still query the database and see the data. While if ransomware encrypts the database - no one can get to the data.