Twas the night before Christmas, when all through the house
not a peripheral was stirring, not even the mouse.
And yet in the darkness and silence, it grew
The crypto monster was whirring, and it's coming to get you.
Cryptography is the art of writing ciphers and codes. Crypto viruses are a particularly evil hostage scheme where YOUR precious information is held for ransom by cyber crooks.
How it works is they will send you an infected file in an email, pretending to be something else. A receipt for a package you may or may not expecting, or payment information from a job you don't actually remember doing. You eagerly open the document, and get some kind of error.
You put it aside as one of those computer things, and carry on with your work. However, silently a program is running in the background of your computer. It starts with your mapped drives. These are usually on your server, and can contain anything from financial documents to family photos. The background program opens the files up, mixes all the information around, then saves the new, now encrypted document.
This will happen for anywhere from a week to a few months. Everything SEEMS ok, a few files won't work, but computers are silly like that aren't they? You carry on for a while in the background crypto works, encrypting more and more files.
Then one day, Your lovely background of playing horses is replaced with a big shield and a big warning - Your Personal Files are encrypoted! (Spelling mistake included for extra offensiveness) and suddenly you can't just carry on.
Family photos, your music collection, all your financial documents, MYOB, Ostendo, Your CV. All locked up. Unfortunately this is 100% the case. The encryption is the same as used by banks to make sure your data is safe - there really is no reversing it with current technology!
Your files are gone, and if you want them back, you have two choices: Pay these criminals anywhere around a thousand dollars, with no promise of retrieving your data anyway, Or you can restore from backups.
You do have a solid backup right? Ah, but last nights backup isn't good enough, those files are already encrypted, IN YOUR BACKUP! One of Crypto lockers evil secrets to success is how it can go undetected for long enough to encrypt as much as it needs to hold you to ransom. In some cases, AllSystemsGo has had to go to backups over a month old to retrieve unchanged files.
In short, If you don't have a solid, tested backup going back in time far enough... You'd better prepare to lose it all.
Check out these links and see how other businesses have fared after not being warned appropriately.