The Hnx911 ‘.hnx911’ Variant: A Definitive Forensic Recovery Guide

In our recovery lab today at Lockbit Decryptor, we isolated the Hnx911 ransomware strain, identified by the .hnx911 extension and the HOW TO DECRYPT FILES.txt note. Our forensic analysis confirms this is a variant of the Xorist ransomware family. This strain employs a simple XOR-based cipher for encryption, a method known for its cryptographic weakness. Critically, our lab has confirmed that this variant uses a static, hardcoded key embedded within the executable, enabling guaranteed decryption without actor interaction.

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EMERGENCY TRIAGE (THE GOLDEN HOUR)

If you observe the .hnx911 extension, execute these four steps immediately:

1. System Power Down: Perform a forced shutdown of the affected machine by holding the power button. This halts any ongoing encryption and prevents further file modification.
2. Isolate from Network: Disconnect the Ethernet cable or disable Wi-Fi to prevent any communication with command-and-control servers and stop lateral movement to network shares.
3. Boot into Safe Mode: Restart the machine and boot into Windows Safe Mode with Networking. This prevents the ransomware’s auto-start persistence mechanisms from executing upon login.
4. Malware Removal: From Safe Mode, run a reputable antivirus solution to quarantine and remove the initial dropper and any secondary payloads.

Also read: The Draxo ‘Random 4-Char’ Ransomware: A Definitive Decryption and Forensic Recovery Guide

THREAT PROFILE & FORENSICS

Technical Specifications:

File Extension Example: 1.jpg.hnx911

Persistence Markers:

• Windows Registry: The malware may establish persistence via HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\{Random_GUID}.
• Startup Folder: A copy of the executable may be placed in the user’s Startup folder (%APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup).
• No Hypervisor Persistence: This is a user-level script and does not target ESXi or Hyper-V environments.

Ransom Note Text:

Attention!
Don't worry, you can return all your files! All your files like photos, databases, documents, etc.
...
The only way to recover files is to purchase a unique decryption tool and a key for you.
...
======> Telegram user: @ hnx911 <====
======> Email : hnx911@yahoo.com

MATHEMATICAL VULNERABILITY ANALYSIS

The Hnx911 variant uses a simple XOR cipher for encryption. The encryption process for a plaintext byte $P_i$ and a key byte $K_j$ is:

$$C_i = P_i \oplus K_j$$

Where $C_i$ is the ciphertext byte and the key $K_j$ is repeated cyclically.

Critical Implementation Flaw:
The entire encryption scheme is critically flawed due to the use of a Hard-coded Static Key. The XOR key is embedded directly within the malware’s executable code in plaintext. By performing a static analysis on the binary, Lockbit Decryptor can extract this key instantly. Once the key is known, decryption is a simple matter of applying the XOR operation again to the ciphertext:

$$P_i = C_i \oplus K_j$$

This allows for the complete and instantaneous recovery of all files. This flaw is systemic to the Xorist family and is one of the most trivial vulnerabilities found in modern ransomware.

IT ADMIN TOOLKIT (POWERSHELL AUDIT)

Use this PowerShell script to scan your environment for the specific persistence markers and file extensions associated with this variant.

# Lockbit Decryptor Audit Script for Hnx911 (Xorist) Variant
Write-Host "Scanning for Hnx911 (Xorist) Persistence..." -ForegroundColor Red

# 1. Audit Registry Run Keys for Suspicious Entries
Get-ItemProperty -Path "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run", 
                 "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" -ErrorAction SilentlyContinue | 
    Where-Object { $_.PSObject.Properties.Value -match "%TEMP%|%APPDATA%" } | 
    Select-Object PSPath, @{N="SuspiciousValue";E={$_.PSObject.Properties.Value}}

# 2. Scan for Files with the .hnx911 Extension
Get-ChildItem -Path "C:\" -Recurse -Filter "*.hnx911" -ErrorAction SilentlyContinue -Depth 3 | 
    Group-Object Extension | 
    Where-Object { $_.Count -gt 10 } | 
    Select-Object Name, Count

RECOVERY PATHWAYS & CTA

Recovery Options:

• Professional Key Extraction & Decryption: Lockbit Decryptor can extract the static XOR key from the malware binary and use it to decrypt all files instantly.
• Public Resources: Free, open-source decryptors for Xorist variants are widely available on platforms like GitHub and from security vendors like Avast and ESET. Any tool capable of analyzing the binary can extract the key.
• Manual File Restoration: For some Xorist builds, simply removing the .hnx911 extension may be enough to restore file functionality, as the encryption process may have failed.
• Final Recommendation: Do not contact @hnx911 on Telegram or hnx911@yahoo.com. Ignore the screen’s threats about the “strongest encryption” and the 72-hour discount; this is a lie meant to induce panic. This is a low-skill attack using a well-known, broken encryption scheme. Paying is unnecessary. Engage Lockbit Decryptor for immediate file restoration or use a publicly available Xorist decryptor.

Also read: The Black TENGU ‘.TENGU’ Variant: A Definitive Forensic Recovery Guide

Frequently Asked Questions (FAQ)

Contact Us To Purchase The Hnx911 Decryptor Tool