Russia unleashed data-wiper virus on Ukraine

These days, there's not really a good way to protect yourself from a virus like that. A lot of this state-designed malware relies on expensive zero-days that can't be mitigated with typical antivirus software, so I can only recommend this:

Backup, backup, backup.

The old "3-2-1" rule should be good enough for anyone who's paranoid about this sort of thing: keep 3 copies of data, on 2 different media, with 1 located offsite. For extra security, I'd recommend switching/supplementing the "1" out to 1 offline backup, if you've got the resources to do that periodically. That way, even if your device is pwned and the Russians dd your root directory, you can reinstall and have your mission-critical data onhand.