*[email protected]**id-**.void

[Content by Gemini 2.5]

As a cybersecurity expert specializing in ransomware, I’ve compiled a detailed resource regarding the ransomware variant identified by the file extension *[email protected]**id-**.void. This specific pattern strongly indicates it is a variant of the prolific STOP/Djvu ransomware family, which has seen numerous iterations over the years. Understanding its characteristics is crucial for effective prevention, remediation, and recovery.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this ransomware variant will be appended to encrypted files, following the format: .[[email protected]]id[random_string].void.
  • Renaming Convention: When a file is encrypted, its original name and extension are preserved, and the ransomware appends its unique identifier string.
    • Example: A file named document.docx would be renamed to document.docx.[[email protected]]id[random_string].void.
    • The [random_string] typically consists of alphanumeric characters, representing a unique victim ID.
    • The void portion acts as the final, static extension for this specific variant, signifying its membership within the broader STOP/Djvu family’s naming conventions.
    • In addition to renaming files, the ransomware drops a ransom note, typically named _readme.txt, in every folder containing encrypted files. This note contains instructions for the victim, including payment demands and contact information (often [email protected] or similar email addresses).

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The STOP/Djvu ransomware family first emerged in late 2017/early 2018 and has since become one of the most active and prevalent ransomware threats. Variants utilizing the .[email]id[id].void pattern, specifically with [email protected], likely began appearing in late 2023 to early 2024, as the family continuously evolves, introducing new contact emails and minor code changes to evade detection and maintain its effectiveness. It’s an ongoing threat with new variants emerging regularly.

3. Primary Attack Vectors

The *[email protected]**id-**.void variant, consistent with the STOP/Djvu family, primarily relies on the following propagation mechanisms:

  • Bundled Software & Pirated Content: This is the most common and successful vector. Victims often download cracked software, key generators (keygens), pirated games, illegal movie downloads, or fake software installers from untrusted websites. The ransomware payload is often discreetly bundled within these seemingly legitimate or desired applications.
  • Malvertising & Drive-by Downloads: Malicious advertisements on legitimate or compromised websites can redirect users to exploit kits or download pages that automatically initiate the ransomware infection without explicit user interaction (drive-by download).
  • Fake Software Updates: Pop-up messages or email notifications prompting users to install urgent software updates (e.g., Flash Player, Java, web browsers) can lead to the download and execution of the ransomware.
  • Email Phishing Campaigns: While less common for Djvu than for some other ransomware families, general phishing emails containing malicious attachments (e.g., seemingly legitimate documents with embedded macros) or links to malicious websites can still be a vector.
  • Adware Bundling: In some cases, the ransomware may be delivered alongside aggressive adware that redirects users to malicious sites or downloads.
  • Pre-existing Malware Infections: Sometimes, the Djvu ransomware is deployed as a secondary payload by other malware already present on the system, such as information-stealers (e.g., Vidar, Azorult, RedLine Stealer). These info-stealers might steal credentials and then download the ransomware to maximize damage.

Remediation & Recovery Strategies:

1. Prevention

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

  • Regular Backups: Implement a robust 3-2-1 backup strategy (3 copies, 2 different media types, 1 offsite/cloud). Ensure backups are isolated from the network to prevent encryption. This is your most reliable recovery method.
  • Software Updates: Keep your operating system, applications, and antivirus software up to date with the latest security patches. Vulnerabilities are often exploited by ransomware.
  • Reputable Antivirus/Anti-Malware: Use a comprehensive, reputable antivirus suite with real-time protection and behavioral detection capabilities. Ensure it’s regularly updated.
  • User Account Control (UAC): Enable UAC and operate with standard (non-administrator) user accounts whenever possible to limit the scope of potential infections.
  • Email Vigilance: Be cautious of unsolicited emails, especially those with attachments or links. Verify the sender before opening anything.
  • Avoid Pirated Software: Do not download or install cracked software, key generators, or illegal content from untrusted sources. This is the primary vector for Djvu variants.
  • Ad Blockers: Use browser extensions that block malicious advertisements and pop-ups, which can prevent redirects to malware sites.
  • Network Segmentation: For organizations, segment networks to limit lateral movement of ransomware in case of an infection.
  • Disable RDP if Unnecessary: If Remote Desktop Protocol (RDP) is not required, disable it. If it is, secure it with strong, unique passwords, multi-factor authentication (MFA), and restrict access via firewalls.

2. Removal

If your system is infected, follow these steps to remove *[email protected]**id-**.void:

  1. Isolate the System: Immediately disconnect the infected computer from the internet and any local networks (unplug Ethernet cable, disable Wi-Fi). This prevents the ransomware from spreading to other devices or communicating with its command-and-control server.
  2. Identify and Terminate Malicious Processes:
    • Boot the computer into Safe Mode with Networking (or Safe Mode if you don’t need network access for initial scanning). This limits the ransomware’s ability to run.
    • Open Task Manager (Ctrl+Shift+Esc) and look for suspicious processes that consume high CPU or memory. Be cautious, as ransomware processes often have legitimate-sounding names.
  3. Scan and Remove:
    • Run a full system scan with your updated reputable antivirus/anti-malware software. Tools like Malwarebytes, Bitdefender, ESET, or similar can often detect and remove the ransomware executable.
    • Consider a second opinion scan with another tool, like the free version of Malwarebytes, to catch anything missed.
    • Crucially, ensure all detected ransomware components are quarantined or deleted.
  4. Check Startup Items: Use msconfig (System Configuration) or Task Manager’s “Startup” tab to disable any suspicious entries that would allow the ransomware to launch on boot.
  5. Delete Temporary Files: Clear temporary files using Disk Cleanup or a tool like CCleaner, as ransomware might leave behind remnants.
  6. Review System Changes: Check for new user accounts, disabled security features, or firewall rule changes made by the ransomware. Revert any unauthorized changes.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • Online Keys: For most recent STOP/Djvu variants, including *[email protected]**id-**.void, decryption is extremely challenging or impossible without the attacker’s private key. These variants generate unique encryption keys for each victim, which are sent to the attacker’s server (online keys). Unless the attackers provide the key (via payment) or law enforcement seizes their servers, your files cannot be decrypted.
    • Offline Keys: In rare cases, if the ransomware fails to connect to its command-and-control server, it might use an “offline key.” If this happens, your files might be decryptable using the Emsisoft STOP Djvu Decryptor. This tool has a database of offline keys collected by researchers. You can identify if an offline key was used by checking the PersonalID.txt file (often found on the desktop) or the ransom note; if the string t1 (or similar) is present at the end of your personal ID, it’s often an offline ID.
    • Paying the Ransom: Paying the ransom is strongly discouraged. There is no guarantee you will receive the decryption key, and it fuels the ransomware economy.
  • Essential Tools/Patches:
    • Emsisoft STOP Djvu Decryptor: This is the primary (and often only) public tool for decrypting files from STOP/Djvu variants. It’s free and updated regularly.
    • Reputable Antivirus/Anti-malware Software: Essential for both prevention and removal.
    • Data Recovery Software: Tools like PhotoRec, Recuva, or Disk Drill might sometimes recover older, unencrypted versions of files if shadow copies were not deleted by the ransomware (though Djvu variants often attempt to delete them).
    • System Restore Points: While often targeted and deleted by ransomware, check if any restore points exist prior to the infection.

4. Other Critical Information

  • Additional Precautions:
    • Info-Stealer Component: A significant characteristic of many recent STOP/Djvu variants, including those with custom extensions like *[email protected]**id-**.void, is their tendency to drop and execute an information-stealing malware (e.g., Vidar, Azorult, RedLine Stealer) before encrypting files. This means that even if you restore your files from a backup, your sensitive information (passwords, cryptocurrency wallets, browser data, etc.) may have already been exfiltrated.
    • Password Reset: If infected, it is imperative to change all passwords for online accounts (email, banking, social media, etc.) immediately after cleaning the system, assuming the info-stealer was successful. Use a different, clean device for this.
    • Financial Monitoring: Monitor bank accounts and credit cards for suspicious activity.
  • Broader Impact:
    • Volume and Persistence: The STOP/Djvu family is notable for its sheer volume of attacks, primarily targeting individual users and small businesses. Its continuous evolution ensures its persistence as a significant threat.
    • Ease of Access for Attackers: The prevalence of its attack vectors (pirated software) makes it easily accessible to a wide range of less sophisticated attackers, contributing to its widespread nature.
    • High Decryption Difficulty: The shift to “online keys” has made recovery without paying the ransom exceptionally difficult, leaving many victims with permanently lost data if they lack backups.
    • Dual Threat (Ransomware + Infostealer): The combination of data encryption and data exfiltration poses a double threat, compounding the damage and privacy implications for victims.

By understanding these aspects, individuals and organizations can better protect themselves and respond effectively to the *[email protected]**id-**.void ransomware variant.