Also, you have to make sure the backup is done through a network - some ransomware will happily encrypt any removable media you happen to plug in to your computer.
Unless you have petabytes of storage, a very slow internet connection, or need to operate at an enterprise scale, this really hasn't been true for years:
1. Go to CrashPlan.com 2. Download and run the installer 3. Pay your choice of nothing to $12.50/month depending on how many computers you have and whether you choose to backup to their cloud, a friend's computer, an external drive, or any combination of the three.
1. Go to Backblaze.com 2. Download and run the installer 3. Pay $5/month
1. Pick one of the many AWS Glacier backup tools 2. Set a minimum retention policy in Glacier 3. Pay for your total storage usage
The key part is the use of a service for which you do not have admin rights and which has some sort of minimum retention period. Even Dropbox has that now.
https://www.dropbox.com/en/help/113
The main thing I'd worry about is locking down your default browsing profile & otherwise making it less likely to be compromised in the first place. I would imagine for most people on HN, the greatest inconvenience would be dealing with the mess if malware got access to your employer/customer's servers, data, etc. That's harder (e.g. rigidly separate accounts or computers, reducing the amount of access you operate with normally, etc.) but avoiding that mess is worth it.
Many ransomware variants target network attached backups, eg [1]. They often target USB attached storage too.
Offsite backup ftw. We restored from Glacier.