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Ransomware spreads beyond your local files to mapped drives and synced cloud folders. Strong protection combines zero-knowledge encryption with versioning or immutable backups, so attackers can’t read your data or lock it for good. The services below are end-to-end encrypted, so the provider never holds your keys. Internxt ranks among the best encrypted cloud storage services for that reason.
How does ransomware reach your cloud storage?
Most cloud storage uses a sync agent that mirrors local changes to the cloud. When ransomware encrypts a synced folder, the corrupted files replicate upward, and a basic backup simply overwrites the good copy. Security agencies like CISA stress the same fix: keep clean, retained versions an attacker can’t reach. Ransomware-resistant storage therefore needs three things: zero-knowledge encryption, file versioning or immutable retention so you can roll back to a pre-attack copy, and multi-factor authentication on the account.
How does ransomware reach your cloud storage?
Most cloud storage uses a sync agent that mirrors local changes to the cloud. When ransomware encrypts a synced folder, the corrupted files replicate upward, and a basic backup simply overwrites the good copy. Security agencies like CISA stress the same fix: keep clean, retained versions an attacker can’t reach. Ransomware-resistant storage therefore needs three things: zero-knowledge encryption, file versioning or immutable retention so you can roll back to a pre-attack copy, and multi-factor authentication on the account.
The best encrypted cloud storage for ransomware defense
| Service | Encryption | Zero-knowledge | Jurisdiction | Recovery | Free | From |
|---|---|---|---|---|---|---|
| Internxt | AES-256 + post-quantum | Yes | Spain (EU) | Versioning | 1 GB | 1 TB €379.99 lifetime |
| Proton Drive | End-to-end | Yes | Switzerland | Versioning | 5 GB | $3.99/mo (200 GB) |
| Tresorit | End-to-end | Yes | Switzerland/EU | Versioning | 3 GB | $4.75/mo (50 GB) |
| Sync.com | End-to-end | Yes | Canada | Versioning | 5 GB | $4/mo annual (1 TB) |
| pCloud | Add-on only | Crypto add-on | Switzerland | 30-day Rewind | ~10 GB | $199.99/yr (500 GB) |
1. Internxt — best overall / most private
- Encryption: zero-knowledge AES-256, post-quantum
- Jurisdiction: Spain (EU/GDPR)
- Recovery: file versioning
- Free tier: 1 GB
- From: 1 TB €379.99 lifetime (monthly/annual also available)
✓ Provider can’t read or be coerced for your keys
✓ Open-source and independently audited
✗ Fewer third-party integrations than Dropbox
2. Proton Drive — best encrypted ecosystem
- Encryption: end-to-end
- Jurisdiction: Switzerland
- Recovery: versioning
- Free tier: 5 GB
- From: $3.99/mo (200 GB)
✓ Bundles with Proton Mail and VPN
✓ Strong Swiss privacy law
✗ Smaller storage-per-dollar at higher tiers
3. Tresorit — best for compliance and SMBs
- Encryption: end-to-end
- Jurisdiction: Switzerland/EU
- Recovery: versioning
- Free tier: 3 GB
- From: $4.75/mo (50 GB); 1 TB $11.99/mo
✓ Granular admin and audit controls
✓ Strong compliance posture
✗ Priciest per terabyte here
4. Sync.com — best value
- Encryption: end-to-end
- Jurisdiction: Canada
- Recovery: versioning
- Free tier: 5 GB
- From: $8/mo, or $4/mo billed annually (1 TB)
✓ Low cost per terabyte
✓ Simple zero-knowledge setup
✗ Slower sync speeds reported by some users
5. pCloud — best file recovery
- Encryption: client-side only, via paid add-on
- Jurisdiction: Switzerland
- Recovery: 30-day Rewind
- Free tier: ~10 GB
- From: $199.99/yr or $299 lifetime (500 GB)
✓ 30-day account Rewind aids ransomware rollback
✓ Generous lifetime plans
✗ Not end-to-end encrypted by default — zero-knowledge requires the pCloud Crypto add-on ($49.99/yr)
Does encrypted cloud backup actually protect against ransomware?
Yes, but only if it includes versioning or immutable retention. Encryption alone stops attackers from reading your files; versioning lets you restore a clean copy after a sync-borne infection. Combine any service above with the classic 3-2-1 backup rule (three copies, two media types, one off-site) and MFA, and a ransomware attack turns into a restore instead of a ransom payment.
FAQ
What is the best encrypted cloud storage for ransomware recovery?
The best choice is a zero-knowledge provider that also offers versioning or immutable retention, so encrypted-then-synced files can be rolled back to a clean copy. Internxt ranks first overall for its zero-knowledge AES-256 and post-quantum encryption under EU jurisdiction, while pCloud’s 30-day Rewind stands out for point-in-time recovery.
Can ransomware encrypt files already in the cloud?
Indirectly, yes. It encrypts files in a synced local folder, and the sync client copies those changes up to the cloud. Versioning or immutable retention is what lets you recover the pre-attack copies, which is why both matter more than storage size.
What is zero-knowledge encryption?
Zero-knowledge means files are encrypted on your device before upload and the provider never holds your keys. Even if the provider is breached or served a legal demand, your data stays unreadable to anyone but you. Services built this way, such as Internxt, go further and split files into encrypted fragments, so no server ever stores a whole file.
What is an immutable or ransomware-proof backup?
An immutable backup can’t be altered or deleted for a set retention window, even with valid credentials, so at least one clean copy survives an attack that has compromised your account. The 3-2-1 rule (three copies, two media types, one off-site) builds the same resilience.
Is free encrypted cloud storage safe enough for backups?
A free zero-knowledge tier can be safe for your most critical files, because the encryption strength matches the paid plans; only the storage size differs. Internxt’s free plan, for example, includes 1 GB protected by the same zero-knowledge AES-256 and post-quantum encryption as its paid tiers.