OFFLINE backups are key. Many cryptolocker virus look for things like USB drives that folks backup to, but leave connected all the time, and will scramble those backups as well.
The key is to take a backup (or snapshot) and then disconnect the drive, or use a program that stores and protects snapshots automatically. I don't know the consumer grade stuff but use Quest Rapid Recovery at the office. It protects about 6 terabytes of data with hourly encrypted snapshots. It's saved the enterprise's bacon more than once.
On my personal machines I use a cloud snapshot service - that wouldn't be much help to you with a troubled Internet connection.
