*[email protected]*.eth

[Content by Gemini 2.5]

This detailed resource provides a comprehensive understanding of the ransomware variant identified by the file extension *[email protected]*.eth, which is a variant of the prolific STOP/Djvu ransomware family.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this ransomware variant is .<original_extension>.<[email protected]>.eth. For example, a file named document.docx would be renamed to [email protected].
  • Renaming Convention: The ransomware encrypts files and appends two suffixes to the original filename. The first suffix is the attacker’s email address ([email protected]), and the second is a unique, fixed extension (.eth) for this specific variant. This pattern is characteristic of STOP/Djvu ransomware, where the .<new_extension> is often unique to a particular variant or batch.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: While the specific [email protected] variant is a recent addition to the STOP/Djvu family, the overarching STOP/Djvu ransomware family itself has been active and continuously evolving since late 2017 or early 2018. New variants like this one emerge regularly, often on a daily or weekly basis, indicating ongoing development and distribution efforts. This particular variant was likely detected in late 2023 or early 2024, aligning with the typical rapid release cycle of new Djvu versions.

3. Primary Attack Vectors

*[email protected]*.eth primarily employs common, high-volume distribution methods characteristic of the STOP/Djvu family, focusing on individual users and small to medium-sized businesses.

  • Propagation Mechanisms:
    • Cracked Software/Software Bundles: This is the most prevalent method. The ransomware is often bundled with pirated software installers, keygens, software cracks, and activators available on torrent sites, shady download portals, and file-sharing networks. Users seeking free or unauthorized software are particularly vulnerable.
    • Malicious Websites and Pop-up Ads: Compromised websites, drive-by downloads, or malicious advertisements (malvertising) can redirect users to landing pages that automatically download the ransomware or trick them into executing it.
    • Fake Software Updates: Pop-up messages or email notifications prompting users to install “critical” software updates (e.g., Flash Player, Java, web browsers) can deliver the ransomware payload.
    • Email Phishing Campaigns: Although less common for STOP/Djvu compared to other ransomware families, general phishing emails with malicious attachments (e.g., infected Word documents, ZIP files containing executables) or links to compromised sites can also serve as an entry point.
    • Unsecured Remote Desktop Protocol (RDP): While not the primary method, poorly secured RDP endpoints can be brute-forced or exploited to gain access and deploy the ransomware manually.
    • USB Drives: In some cases, infection can occur through infected USB drives that have been used on compromised machines.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to defend against *[email protected]*.eth and similar ransomware threats:

  • Regular Data Backups: Implement a robust 3-2-1 backup strategy: at least three copies of your data, stored on two different media types, with one copy off-site or air-gapped (disconnected from the network). Test your backups regularly.
  • Keep Software Updated: Regularly patch operating systems, applications (especially web browsers, office suites, and security software), and firmware to close known vulnerabilities.
  • Use Reputable Antivirus/Anti-malware: Install and maintain a comprehensive, real-time antivirus solution with ransomware protection capabilities. Ensure its definitions are always up-to-date.
  • Exercise Email Vigilance: Be cautious of suspicious emails, especially those with unexpected attachments or links. Verify the sender’s identity before opening anything.
  • Avoid Pirated Software: Never download or use cracked software, keygens, or activators. These are primary vectors for STOP/Djvu ransomware and often contain additional malware like info-stealers.
  • Enable Firewall: Configure your firewall to block unauthorized inbound and outbound connections.
  • User Account Control (UAC): Do not disable UAC; it provides an essential layer of protection against unauthorized changes.
  • Network Segmentation: For organizations, segment networks to limit lateral movement of ransomware if an infection occurs.
  • Disable SMBv1: If not strictly necessary, disable SMBv1 on Windows systems as it contains vulnerabilities exploited by some malware.

2. Removal

Removing the ransomware executable is a critical first step, but it does not decrypt files.

  • Infection Cleanup (Step-by-step):
    1. Isolate the Infected System: Immediately disconnect the infected computer from the network (unplug Ethernet cable, disable Wi-Fi). This prevents further spread to other devices.
    2. Identify and Terminate Malicious Processes: Use Task Manager (Ctrl+Shift+Esc) to look for suspicious processes running in the background. If unsure, proceed to the next step.
    3. Boot into Safe Mode: Restart your computer and boot into Safe Mode with Networking. This loads only essential services and drivers, often preventing the ransomware from running or interfering with removal tools.
    4. Run a Full System Scan: Use your updated antivirus/anti-malware software to perform a thorough scan of the entire system. Reputable tools like Malwarebytes, ESET, Avast, or Kaspersky are effective. Allow the software to quarantine or remove all detected threats.
    5. Check for Persistence Mechanisms:
      • Registry Editor (regedit.exe): Check HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run and HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run for suspicious entries that could restart the ransomware.
      • Task Scheduler (taskschd.msc): Look for newly created scheduled tasks designed to re-execute the malware.
    6. Review Hosts File: Ransomware often modifies the hosts file (C:\Windows\System32\drivers\etc\hosts) to block access to security websites or update servers. Restore it to its default state if modified.
    7. Delete Ransomware Files: After scanning, manually delete any remaining ransomware executables or associated files that the antivirus may have missed (often found in %TEMP%, %APPDATA%, or ProgramData directories).
    8. Reboot and Rescan: Reboot your computer into normal mode and perform another full system scan to ensure all traces are gone.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • Possible (Offline ID): Decryption is often possible for STOP/Djvu variants like [email protected] if the ransomware used an “offline key” during encryption. An offline key is used when the malware cannot connect to its command-and-control (C2) server, making it fall back to a pre-defined, static key. If this key is known and publicly available, files can be decrypted.
    • Difficult (Online ID): Decryption is significantly more challenging if the ransomware used an “online key.” An online key is unique to each infection and is generated by the C2 server. Without this specific key for your infection, decryption is virtually impossible using public tools.
    • Emsisoft Decryptor: The Emsisoft Decryptor for STOP/Djvu Ransomware is the primary and most reliable tool for attempting decryption. This tool is regularly updated with new keys as they are discovered (especially for offline IDs).
      • How it works: The decryptor attempts to identify the specific ID used for your encryption (found in the PersonalID.txt or info.txt file dropped by the ransomware, or within the ransom note filename itself). It then tries to match this ID with known keys.
  • Essential Tools/Patches:
    • Emsisoft Decryptor for STOP/Djvu: Download this tool ONLY from Emsisoft’s official website (decrypter.emsisoft.com/stop.zip).
    • Data Recovery Software: Tools like PhotoRec, Recuva, or EaseUS Data Recovery may sometimes recover previous versions of files or deleted Shadow Volume Copies (though STOP/Djvu often attempts to delete these using vssadmin.exe). Success is not guaranteed.
    • System Restore: While ransomware often disables System Restore points, check if any uninfected restore points exist to revert your system.
    • Windows Updates: Ensure your Windows operating system is fully updated to patch any vulnerabilities.

4. Other Critical Information

  • Additional Precautions:

    • Info-stealer Co-infection: A significant characteristic of STOP/Djvu ransomware is its frequent bundling with information-stealing malware (e.g., Vidar, RedLine, Azorult, SmokeLoader). Even if you decrypt your files, assume that your sensitive data (passwords, cryptocurrency wallets, browser cookies, documents) may have been exfiltrated. It is crucial to change all passwords for online accounts and monitor financial accounts for suspicious activity. Consider reinstalling your operating system after data recovery to ensure a clean slate.
    • Hosts File Modification: This variant, like others in its family, attempts to modify the hosts file to block access to security websites and update servers, hindering victims from seeking help or updating their antivirus definitions.
    • Deletion of Shadow Copies: The ransomware typically runs commands like vssadmin.exe Delete Shadows /All /Quiet to remove System Restore points and Shadow Volume Copies, making built-in Windows recovery methods ineffective.
    • Persistence: It often creates registry entries or scheduled tasks to ensure it runs every time the system starts, even if the primary executable is removed, unless these entries are also cleaned.

  • Broader Impact:

    • Widespread Impact on Individuals: Due to its reliance on cracked software and torrents, STOP/Djvu variants disproportionately affect individual users and small businesses seeking “free” software, making it one of the most common ransomware families encountered by home users.
    • High Volume of Variants: The constant release of new variants with different extensions and keys makes it a persistent cat-and-mouse game for security researchers developing decryptors. Each new variant requires new analysis to determine if decryption is possible.
    • Financial and Privacy Risk: Beyond data encryption, the co-infection with info-stealers adds a layer of privacy and financial risk, as personal credentials and financial information can be stolen.

Combating *[email protected]*.eth and similar threats requires a layered approach focusing on prevention, robust cybersecurity hygiene, and a clear understanding of recovery limitations and possibilities.