Can ransomware infect encrypted backups?

Yes. Encryption at rest protects backups from unauthorized reading, but it does not stop ransomware: if attackers gain access through the backup application or compromised credentials, they can encrypt, corrupt, or delete the backups regardless of at-rest encryption. And a backup can quietly contain ransomware that was copied into it before detection.

This is the gap Elastio closes — it inspects inside backups to confirm the data they hold is actually free of ransomware, rather than assuming an encrypted or immutable backup is a clean one.