A popular hack of the last year that I have seen a few times is the ransom: a virus infects your server and encrypts the entire hard disk making all the data on it inaccessible. To get it unlocked, the hacker demands a ransom. I am still seeing businesses affected by it.
The best defense is proper backup. If you can confidently wipe the data store clean and restore it from your current backup, you don’t have a problem with this scam. In our audits for new clients, we find MOST backup is failing or is inadequate to meet the requirements of the business. Scary but true. If you don’t have regular backup restore tests that work for everything you have on computers, then you are probably one of those statistics.