How to Actually Protect Your NAS from Ransomware in 2026 — Why Most Guides Get It Wrong, and What to Do Instead

If you've searched for "how to protect your Synology NAS from ransomware," you've probably read the same article ten times with a different header image. Enable snapshots. Keep DSM updated. Use a strong password. Enable two-factor authentication.

None of that advice is wrong. But none of it answers the question that actually keeps NAS owners up at night: what happens if ransomware is already running on your Windows machine when it happens? And what happens if someone physically walks out with your drives?

Those are two completely different problems, and most guides treat them as one. That's why most guides leave you with half a solution.

The Two Threats Nobody Separates

Before we get into configuration, it's worth spending a minute on threat modelling, because the fix for one problem actively does nothing for the other.

The first threat is confidentiality. Someone gains access to your NAS files and reads them — a stolen drive, a DSM vulnerability, a compromised NAS package, a disgruntled employee with physical access. The data is readable. Depending on what you store, that could mean client records, financial data, legal documents, health information.

The second threat is availability. Someone prevents you from accessing your own data. Ransomware is the obvious example — it doesn't care what's in your files, it just overwrites or encrypts them and demands payment. Hardware failure does the same thing accidentally.

These feel like the same problem. They're not. A snapshot strategy protects availability but does nothing if someone physically takes your drives and reads them. Encrypting your files before they reach the NAS protects confidentiality but does nothing if ransomware overwrites those encrypted files from your own Windows machine. You need both layers, and they need to be independent of each other.

Why Synology's Built-In Encryption Doesn't Fully Solve Confidentiality

Synology ships with several encryption options and it's worth being precise about what each one actually protects:

• Shared Folder Encryption (formerly VolumeCrypt): Encrypts the folder at rest using AES-256. But the NAS holds its own decryption key. When mounted, a compromised DSM session or physical access to a running NAS exposes the plaintext.
• SMB3 Encryption: Secures data in transit between Windows and the NAS. It doesn't touch data at rest.
• HTTPS interface: Secures the management channel only.

The only approach that fully solves confidentiality: encrypt on the client machine before the data leaves it. The NAS receives ciphertext. It stores ciphertext. It cannot decrypt it because it never had the key.

Why Client-Side Encryption Alone Still Leaves You Exposed

The obvious approach to client-side encryption is mounting the NAS share as a Windows drive letter (e.g. Z:) and running VeraCrypt containers on top of it. Here's the problem: that encrypted volume is still mounted as Z:. Windows knows it exists. Ransomware running on your Windows machine scans all mounted drives, finds Z:, and starts re-encrypting whatever it finds there. Confidentiality preserved; availability gone.

The Architectural Insight: Invisible SMB Connections

Standard Windows file access goes through the Windows SMB redirector (MRxSmb). Every application running on your Windows session can see mapped drives.

Now consider a different approach: What if the NAS connection didn't go through Windows' SMB stack at all?

An application like VaultNX implements its own TCP-level SMB client. It establishes a direct connection to the NAS on port 445 without involving Windows' SMB stack. No drive letter is created. The share doesn't appear in Explorer. The vault is architecturally invisible to ransomware scanning your Windows session.

Hardened Configuration Checklist

Final Thought

Treat confidentiality and availability as what they are: two separate engineering problems. Client-side encryption with a key that never touches the NAS solves the first. An invisible SMB connection that ransomware can't enumerate solves most of the second. Immutable snapshots and air-gapped backups solve the rest.