Filecoder (.encrypt) NAS Ransomware Decryptor
If your NAS system has been attacked and your files now end in “.encrypt”, you’re likely facing the Filecoder ransomware — a Linux-targeting cryptovirus affecting storage platforms like Synology, QNAP, and other NAS devices.
Our team has developed a specialized Filecoder NAS Decryptor. It works on ransomware variants that:
- Rename files with the .encrypt extension
- Leave ransom notes named README_FOR_DECRYPT.txtt
- Encrypt files using OpenSSL AES (recognized by Salted__ headers)
- Impact Linux-based NAS systems only — not Windows PCs
We deliver safe, professional ransomware recovery without paying the attackers.
How Our Filecoder NAS Ransomware Decryptor Works
Our decryptor was built after deep analysis of Filecoder variants in the wild. It reconstructs the encryption method used by the malware and enables file restoration through a secure, sandboxed environment.
Here’s how our process works:
- Reverse Engineering: Our team studied encryption routines using OpenSSL and created a recovery utility that mimics decryption.
- Cloud-Based Decryption: All operations are handled remotely inside a secure, isolated cloud sandbox.
- Pre-Recovery Validation: We analyze your encrypted files and ransom note to confirm compatibility with our decryptor. Only then do we proceed.
This ensures precision recovery with zero risk to your original infrastructure.
Filecoder Decryption & Recovery: Step-by-Step
Step 1: Identify the Infection
Check for:
- Files ending with .encrypt
- Presence of the README_FOR_DECRYPT.txtt ransom note
- File headers beginning with Salted__
Step 2: Secure Your Environment
Disconnect the NAS device from all networks and disable services like SMB, NFS, and SSH. Do not reboot or reset the system.
Step 3: Send Samples
Submit:
- 1–3 encrypted files
- The ransom note
- (Optional) A matching original version of one encrypted file
Step 4: Confirm Decryptor Compatibility
We verify encryption patterns, analyze file headers, and confirm if your case is supported.
Step 5: Launch Decryption Process
Once verified, our decryptor is deployed securely, either remotely or in a cloud-based sandbox.
Step 6: Recover Your Data
Files are restored in batches, verified for integrity, and returned safely.
What to Do Immediately After Infection
- Unplug the NAS from the internet
- Avoid rebooting or performing a factory reset
- Do not use random decryptors
- Save ransom notes and encrypted file samples
- Contact a ransomware recovery expert immediately
Keep Calm – Our Expert Team Has You Covered
We specialize in ransomware targeting NAS devices. Our services are used by organizations around the world facing encryption threats on:
- Synology (DSM), QNAP (QTS), and other Linux NAS
- eCh0raix, DeadBolt, QNAPCrypt, and Filecoder infections
Our team includes:
- Certified cryptographic analysts
- Linux system recovery specialists
- Data forensics and ransomware containment experts
We guarantee:
- Transparent communication
- Recovery within 12–48 hours (typical cases)
- No upfront payment if we can’t confirm recovery
Filecoder (.encrypt) Ransomware: Key Facts & Insights
- First Detected: Late 2024
- Target Systems: Linux-based NAS (Synology, QNAP)
- File Extension Used: .encrypt
- Ransom Note Name: README_FOR_DECRYPT.txtt
- Encryption Method: OpenSSL AES, Salted__ header
- AV Detection Name: Linux/Filecoder.a
- Infection Method: Exposed SSH ports, weak admin credentials
- Data Exfiltration: None confirmed
- Public Decryptor: Not available as of 2025
What is Filecoder NAS Ransomware?
Filecoder (.encrypt) is a ransomware strain designed to target NAS environments using Linux-based operating systems. It encrypts data with AES algorithms through OpenSSL and leaves behind ransom notes asking for Bitcoin payments.
This strain is:
- Likely a fork of eCh0raix/QNAPCrypt
- Script-driven with no advanced payloads or lateral movement
- Focused on encrypting, not stealing, data
Infections are typically isolated to NAS volumes. Windows machines connected via mapped drives are not infected, but files may be encrypted indirectly.
Indicators of Compromise (IOCs)
File-Based IOCs
- .encrypt file extensions
- README_FOR_DECRYPT.txtt notes in each folder
- Files starting with Salted__ header (OpenSSL)
Network-Based IOCs
- TOR communication attempts logged in firewall
- Unusual SSH activity from international IPs
Behavioral IOCs
- Snapshots or backups deleted
- Incomplete encryption in some directories
- Logs in /var/log/ cleared or missing
Modus Operandi: How Filecoder Works
The attack begins by accessing vulnerable NAS devices via exposed SSH or misconfigured web panels. Once inside:
- The malware runs an encryption script using OpenSSL
- Files are renamed with .encrypt and overwritten in-place
- Snapshots and system logs may be deleted
- A ransom note is dropped instructing victims to pay in Bitcoin via a TOR portal
The ransomware does not leave persistence or attempt to move laterally. It performs a one-time lock and exits.
Preventive Measures for Filecoder Attacks
To reduce the risk of infection:
- Disable public access to NAS admin panels
- Enforce strong passwords and enable 2FA
- Update firmware and DSM/QTS software regularly
- Limit access to SSH and use port whitelisting
- Use immutable or offsite backups
- Monitor NAS logs for failed login attempts or odd IP activity
Recovery Checklist for Victims
What to Do:
- Keep encrypted files and ransom notes unchanged
- Save a copy of the NAS system logs if accessible
- Contact an expert team before taking recovery steps
What to Avoid:
- Do not reformat or reset your NAS
- Don’t rely on online decryptors or free tools
- Avoid paying the ransom — results are not guaranteed
The Filecoder Ransom Note – What It Contains
Ransom notes left by Filecoder are usually titled README_FOR_DECRYPT.txtt. They are straightforward and unbranded. Key contents include:
- A TOR website address
- Unique victim ID
- Instructions to upload 2–3 test files
- A Bitcoin address or payment page
Ransom note excerpt:
“Your files are encrypted. Do not try to restore them. You can upload 3 files for free decryption. Visit our portal to get the key.”
Filecoder Attacks by Platform
Synology DSM (DiskStation Manager)
- Entry via outdated DSM panels or exposed port 5000/5001
- Encryption targets: /photo, /homes, /web, /data
- Snapshot deletion via command line
QNAP QTS
- Attacks launched through misconfigured MyQNAPCloud
- Affected folders: /Public, /Multimedia, /Download
- Behavior mirrors eCh0raix, including recursive note dropping
Generic Linux NAS (e.g., OpenMediaVault, TrueNAS)
- Deployed via brute-force SSH or shell scripts injected via cron
- Encryption may be inconsistent or partial
Windows Clients
- Not directly infected
- Files may be encrypted if stored on mapped NAS shares
Conclusion
If your NAS has been locked by Filecoder ransomware, don’t panic — and don’t pay. We offer an effective, tested, and legally compliant way to recover your encrypted data without interacting with attackers.
With our purpose-built decryptor, technical expertise, and fast response model, we help businesses and individuals restore operations with minimal disruption.
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