*[email protected]**id-**.void

[Content by Gemini 2.5]

The ransomware variant identified by the file extension *[email protected]**id-**.void is a clear indicator of an infection, most commonly associated with the STOP/Djvu ransomware family or one of its numerous derivatives. The specific naming convention, particularly the use of an email address ([email protected]) and a unique ID, is a hallmark of this widespread ransomware group. This detailed resource will provide both a technical breakdown and practical recovery strategies to help the community combat this threat.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    The exact file extension appended to encrypted files will follow the pattern:
    [email protected][unique_victim_ID].void
    For example, if a file’s unique victim ID is A1B2C3D4E5F6, the extension would be [email protected].

  • Renaming Convention:
    The ransomware encrypts files and then renames them by appending this complex extension. The original filename and its extension are preserved as part of the new name, making it immediately apparent which files have been compromised.
    Example:

    Additionally, the ransomware typically drops a ransom note file, often named _readme.txt, in every folder containing encrypted files. This note contains instructions on how to contact the attackers (usually via the provided email address) and the ransom demand.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    While [email protected] refers to a specific variant, the underlying STOP/Djvu ransomware family has been active since late 2017 and continues to evolve, releasing new variants almost daily. This particular variant using the [email protected] contact email was likely observed in late 2023 to early 2024, fitting within the continuous activity of the broader STOP/Djvu operation. Its outbreak is characterized by a steady stream of individual infections rather than a single, massive global event, making it a persistent low-to-medium-level threat.

3. Primary Attack Vectors

The STOP/Djvu ransomware family, including the [email protected][ID].void variant, primarily relies on social engineering and exploiting user vulnerabilities. The main propagation mechanisms include:

  • Cracked Software/Pirated Content: This is by far the most prevalent method. Users download pirated software, cracked games, keygens, or activators from torrent sites or unreliable download portals. The ransomware is bundled within these seemingly legitimate, but malicious, installers.
  • Phishing Campaigns: While less common for Djvu than for some other ransomware families, targeted or broad phishing emails containing malicious attachments (e.g., seemingly legitimate documents with embedded macros) or links to compromised websites can still be used.
  • Malicious Advertisements (Malvertising): Compromised ad networks or rogue advertisers can redirect users to exploit kits or directly download malicious payloads disguised as software updates or legitimate programs.
  • Remote Desktop Protocol (RDP) Exploits (Less Common for Djvu): While some ransomware families heavily rely on RDP brute-forcing or exploitation, it’s not a primary method for STOP/Djvu, which largely focuses on individual user compromise through file downloads. However, weak RDP credentials or unpatched vulnerabilities can still be an entry point.
  • Software Vulnerabilities (Less Common for Djvu): Exploiting critical vulnerabilities in operating systems or widely used software (like unpatched SMB vulnerabilities, e.g., EternalBlue) is more characteristic of worms or enterprise-level ransomware, not typically the initial infection vector for Djvu variants.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are the most effective defense against *[email protected]**id-**.void and similar ransomware variants:

  • Regular, Offline Backups: Implement a robust backup strategy following the 3-2-1 rule (3 copies of data, on 2 different media, 1 offsite/offline). Ensure backups are regularly tested and kept isolated from the network to prevent encryption.
  • Software and OS Updates: Keep your operating system (Windows, macOS, Linux) and all software (web browsers, antivirus, productivity suites) updated with the latest security patches. This closes known vulnerabilities that attackers could exploit.
  • Reputable Antivirus/Endpoint Detection and Response (EDR): Install and maintain a comprehensive antivirus or EDR solution. Ensure it’s always active and its definitions are up-to-date.
  • Email Security & User Training: Implement strong spam filters and email gateway security. Educate users about phishing, suspicious attachments, and links. Emphasize caution when downloading files from unknown sources.
  • Strong Passwords & Multi-Factor Authentication (MFA): Use complex, unique passwords for all accounts and enable MFA wherever possible, especially for remote access services like RDP and VPNs.
  • Disable/Secure RDP: If RDP is not essential, disable it. If it must be enabled, restrict access to trusted IPs, use strong passwords, and consider implementing a VPN for access.
  • Application Whitelisting: Implement application whitelisting to prevent unauthorized executables (like ransomware) from running on your systems.
  • Network Segmentation: Divide your network into segments to contain potential outbreaks and limit lateral movement of ransomware.
  • Ad Blockers/Script Blockers: Use browser extensions that block malicious ads and scripts to reduce exposure to malvertising.

2. Removal

Infection cleanup requires careful steps to ensure the ransomware is completely eradicated. Do not attempt decryption or recovery until the ransomware is fully removed.

  1. Isolate Infected Systems: Immediately disconnect the infected computer(s) from the network (unplug Ethernet cable, disable Wi-Fi). This prevents further spread to other devices.
  2. Identify & Terminate Malicious Processes:
    • Boot the infected system into Safe Mode with Networking if possible. This loads only essential services, potentially preventing the ransomware from fully executing.
    • Use Task Manager (Ctrl+Shift+Esc) to identify suspicious processes. Look for high CPU/memory usage from unfamiliar executables. However, ransomware processes can be evasive.
  3. Run Full System Scans:
    • Perform a deep scan with your reputable antivirus/anti-malware software (e.g., Malwarebytes, Windows Defender, ESET, Sophos). Ensure the definitions are up-to-date (if in Safe Mode with Networking, it might update).
    • Consider using a second opinion scanner or a bootable rescue disk from a trusted vendor.
  4. Remove Persistence Mechanisms:
    • Check common ransomware persistence locations:
      • Startup Folders: shell:startup
      • Registry Run Keys: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run, HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
      • Scheduled Tasks: Use Task Scheduler to look for newly created or suspicious tasks.
    • Delete any suspicious entries.
  5. Clean Temporary Files: Delete temporary files (%temp%) and browser caches, as ransomware components might reside there.
  6. Change All Passwords: After confirming the system is clean, change all passwords, especially for network shares, cloud services, and any accounts accessed from the infected machine.

3. File Decryption & Recovery

  • Recovery Feasibility:
    The possibility of decrypting files encrypted by *[email protected]**id-**.void (a STOP/Djvu variant) depends heavily on whether an “online” or “offline” key was used during encryption.

    • Online Key: If the ransomware successfully communicated with its command-and-control (C2) server, it uses a unique “online” key generated specifically for the victim. Decryption is extremely difficult, if not impossible, without the attacker’s master key. Most STOP/Djvu variants use online keys.
    • Offline Key: If the ransomware failed to connect to its C2 server, it might resort to using a static, pre-defined “offline” key. In such cases, if this specific offline key has been recovered by security researchers from previous infections, decryption might be possible.

  • Methods or Tools Available:

    1. Emsisoft Decryptor for STOP/Djvu: This is the primary and most reliable tool for STOP/Djvu decryption. It is developed in collaboration with victims and security researchers. You can download it from the Emsisoft website or No More Ransom project.
      • How it works: You provide encrypted files and their corresponding ransom notes (_readme.txt). The decryptor attempts to identify the specific variant and the encryption key type (online/offline). If an offline key is used and known, it can decrypt files. If an online key is used, it will inform you, and decryption is currently not possible without the attacker’s key.
      • Important: The success rate for online keys is very low. However, it’s always worth trying, as new keys are sometimes recovered.
    2. Shadow Volume Copies (VSS): The ransomware typically attempts to delete Shadow Volume Copies (VSS) using commands like vssadmin delete shadows /all /quiet. However, sometimes it fails, or older copies might remain. You can try to recover previous versions of files or folders via Windows’ built-in “Previous Versions” tab (right-click on a folder/file -> Properties -> Previous Versions).
    3. Data Recovery Software: For files that were deleted (rather than encrypted in place) by the ransomware or were temporary files, data recovery software (e.g., PhotoRec, Recuva) might be able to recover some unencrypted data, but success is not guaranteed and often recovers fragmented or corrupt files.
    4. Backups: The most reliable method of recovery is always through clean, offline backups. Restore your data from a point before the infection occurred.

  • Essential Tools/Patches:

    • For Prevention:
      • Microsoft Windows Update Service (for OS patches)
      • Antivirus/EDR software (e.g., Windows Defender, Malwarebytes, Sophos, CrowdStrike)
      • Web browser with strong security features (Chrome, Firefox, Edge)
      • Password Manager & MFA tools
    • For Remediation/Decryption:
      • Emsisoft Decryptor for STOP/Djvu Ransomware
      • Malwarebytes Anti-Malware (for removal)
      • Windows built-in “System Restore” or “Previous Versions” (for VSS recovery attempts)
      • Bootable anti-malware rescue disks (e.g., Kaspersky Rescue Disk, Avira Rescue System)

4. Other Critical Information

  • Additional Precautions:

    • Do NOT Pay the Ransom: Paying the ransom incentivizes attackers, provides no guarantee of decryption (you might not get a working decryptor, or it might be incomplete), and could mark you as a willing target for future attacks.
    • Be Wary of Fake Decryptors: Many fake decryption tools circulate online, often bundled with more malware or designed to steal your money. Only use tools from reputable cybersecurity vendors (like Emsisoft, Avast, Kaspersky) or official projects like “No More Ransom.”
    • Collect Evidence: Before cleanup, if possible and safe, collect the following: the full ransom note (_readme.txt), a few encrypted files (to upload to analysis sites like ID Ransomware), and any suspicious executables found. This helps researchers improve decryptors and understand the variant.
    • Report the Incident: Report the ransomware attack to your local law enforcement agencies (e.g., FBI IC3 in the US, National Cyber Security Centre in the UK) or relevant cybercrime units.

  • Broader Impact:
    The *[email protected]**id-**.void variant, like other STOP/Djvu variants, primarily targets individual users and small businesses rather than large enterprises. Its broader impact includes:

    • Significant Data Loss: For victims without adequate backups, critical personal documents, photos, and work files can be permanently lost.
    • Financial Strain: Beyond potential ransom payments, recovery involves costs for IT services, new hardware, and lost productivity.
    • Psychological Distress: Dealing with data loss and the feeling of violation can cause significant stress and anxiety for individuals.
    • Disruption of Operations: For businesses, even small-scale infections can halt operations, leading to reputational damage and financial losses from downtime.
    • Contribution to Cybercrime Economy: Each successful infection, whether a ransom is paid or not, helps refine the attackers’ methods and finances their ongoing operations, perpetuating the ransomware threat.

By understanding the technical aspects and implementing robust prevention and recovery strategies, individuals and organizations can significantly mitigate the risk posed by the *[email protected]**id-**.void ransomware variant and contribute to a safer digital environment.