I’m confused about protecting backups from ransomware. Online, people say that backups are the most critical aspect to recovering from a ransomware attack.
But how do you protect the backups themselves from becoming encrypted too? Is it simply a matter of having totally unique and secure credentials for the backup medium?
Like, if I had a Synology NAS as a backup for my production environment’s shared storage, VM backups, etc, hooked up to the network via gigabit, what stops ransomware malware from encrypting that Synology too?
Thanks in advance for the feedback!
If your backups are visible from the targeted systems, you are doing it wrong. Done right, a backup utility at most only uses an agent on the systems to be able to contact them to get the data and the backups are not reachable.
Have a look at how BackupPC works, not even an agent, it accesses network shares to get the data:
I’ll check out backupPC. What is the most common/best practices way to make sure the backup medium isn’t accessible from any endpoints on the network?
Unplug it after the backup.
Immutable/offline backups. If you backup to local physical media (HDD/tape), physically disconnect/eject it and store it somewhere safe. If you back up to cloud storage (S3, etc), many of them have immutability options. If configured properly nobody (not even you) can delete or modify the backups (within the specified time period).
Look into the 3-2-1 strategy. Also: At least one Backup should be taken offline after the backup is done. This might be done via Tapes on a Tapelibary, where you would put your Used tapes into a fireproof safe (certified for Tape fire protection - ask me if you dont know what that means). Those backups that are not connected to a network are most reliable in such a scenario. Most encrypters encrypt right away and thus offline/archived backups are most likely not already affected.
If your trojan was keeping itself silent for a couple of months (some specialised do that) even your archives are at risk. In such a situation mostly the only solution is to build from fresh.
The backups are on a separate system with different credentials. One copy of the backups is sent to online storage that is immutable. You set a retention policy and then you can’t delete, overwrite, or change the backups.
3-2-1 standard is what saves you.
