Feature / Platform	Dropbox	OneDrive	Google Drive	Local NAS
Version History	✅ 30–180 days depending on plan	✅ 30 days (Personal), 93+ days (Business)	✅ 30 days or 100 versions	⚠️ Manual setup (e.g., Btrfs, snapshots)
Rewind Entire Folder/Account	✅ Full rewind (Professional/Business)	✅ Entire OneDrive (via ransomware recovery)	❌ No folder rewind; manual per-file	⚠️ If snapshotting is configured
Deleted File Recovery	✅ Up to 180 days	✅ Recycle Bin (93+ days Business)	✅ 30 days by default	❌ Unless backup/snapshot systems are present
Automatic Ransomware Detection	⚠️ None built-in	✅ Microsoft detects and alerts	❌ No direct detection	❌ Not built-in
Restore En Masse	✅ Rewind	✅ Ransomware Recovery Tool	❌ Manual only	⚠️ Scripted restore possible
Requires Pro Plan	✅ Rewind requires Professional plan	✅ Full features on Microsoft 365 plans	❌ Basic versioning available to all	✅ Requires admin setup
Shared Folder Exposure Risk	⚠️ Yes (encrypted files sync to others)	⚠️ Yes	⚠️ Yes	⚠️ Yes (if mounted/shared)
Offline Backups Supported	❌ Not natively	❌ Not natively	❌ Not natively	✅ Strong, if configured
Immutability Support	❌ No	❌ No	❌ No	✅ With proper setup (e.g., ZFS snapshots)

🏁 Summary

• Dropbox: Strong versioning and full Rewind recovery, but limited automatic detection.
• OneDrive: Best resilience for general users due to ransomware detection, alerts, and full account restore.
• Google Drive: Basic versioning only; weak against mass ransomware without manual work.
• Local NAS: Can be extremely resilient if configured with snapshots or offline backups, but vulnerable by default.
  

✅ Best Ransomware Defence Strategy

Platform	Recommendation
Dropbox	Use Professional or Business plan with Rewind; supplement with offline backups
OneDrive	Use with Microsoft 365 Business for alerts + recovery
Google Drive	Use with third-party backup (e.g. Spanning, Backupify)
Local NAS	Implement automated snapshots and offline backup rotation