Learn how to prove backup immutability for cyber insurance renewals. Discover platform-specific proofs and what underwriters accept as sufficient evidence.
Backup immutability means backups cannot be altered, deleted, or encrypted once written—a critical requirement for ransomware recovery. Underwriters verify immutability through platform-specific controls: AWS S3 Object Lock (compliance or governance mode), Azure Blob Storage immutable storage policies, and Veeam hardened repositories. These controls block deletion for a configured retention period, even if credentials are compromised. Screenshots showing Object Lock enabled, retention period set, and compliance mode active provide verifiable proof. Industry evidence shows immutable backups are assessed for SEC Rule 17a-4(f) and FINRA Rule 4511 compliance, making them legally binding proof during audits. Common rejections include RAID configurations (no immutability guarantee), cloud sync services (not isolated from ransomware), and password-protected but not immutable backups.
Brokers manually screenshot S3 Object Lock settings, Azure policies, or Veeam configs, then email to underwriters. Underwriters manually verify settings match their requirements.
No standardized proof format; underwriters interpret screenshots differently; unclear what constitutes sufficient retention period; difficult to prove freshness of configuration.
Structured immutability attestation with platform, lock mode, retention period, and last-verified timestamp. API integration to query AWS/Azure/Veeam directly.
Use Evidence Room
Use Evidence Room →“S3 Object Lock blocks permanent object deletion during a customer-defined retention period.”
“S3 Object Lock provides a critical layer in a defense-in-depth approach to data protection against ransomware.”
“Compliance mode blocks deletion by any user, including root account holders, ensuring absolute immutability.”