*.*[email protected]*.devon

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This document provides a comprehensive overview of the ransomware variant identified by the file extension *.*[email protected]*.devon. This variant is a known member of the STOP/Djvu ransomware family, which is notorious for its wide distribution and persistent evolution. The contact email [email protected] is typically found within the ransom note, guiding victims on how to pay the ransom for file decryption.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files encrypted by this variant will have the .devon extension appended to their original filename.
  • Renaming Convention: The typical file renaming pattern is original_filename.original_extension.devon.
    • Example: A file named document.docx would be renamed to document.docx.devon.
    • The [email protected] part is not appended to the file name itself but serves as the primary contact email address found in the ransom note left by the attacker (usually _readme.txt).

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The STOP/Djvu ransomware family, to which the .devon variant belongs, first emerged in late 2018/early 2019 and has been continuously evolving with new extensions released almost daily. The .devon variant is one of many such iterations detected throughout 2023 and into 2024, indicating ongoing activity and development.

3. Primary Attack Vectors

*.*[email protected]*.devon (as a STOP/Djvu variant) primarily propagates through social engineering and deceptive tactics rather than exploiting complex network vulnerabilities. Its main attack vectors include:

  • Bundled Software/Cracked Software: This is the most prevalent method. Users often download seemingly legitimate but compromised software cracks, key generators, activators, or pirated applications from untrusted websites. These downloads contain the ransomware payload disguised as part of the desired software.
  • Fake Software Updates: Pop-ups or alerts promoting fake updates for common software (e.g., Adobe Flash Player, web browsers) that, when clicked, download and execute the ransomware.
  • Malvertising: Malicious advertisements on legitimate websites that redirect users to compromised sites or initiate drive-by downloads.
  • Email Phishing Campaigns: Although less common for STOP/Djvu compared to other ransomware families, carefully crafted phishing emails with malicious attachments (e.g., seemingly legitimate invoices, resumes, or shipping notifications) or links to infected websites can be used.
  • Remote Desktop Protocol (RDP) Exploits: In some cases, weak RDP credentials or unpatched RDP vulnerabilities can be exploited to gain unauthorized access and deploy the ransomware manually.
  • Compromised Websites/Downloads: Downloading files from less reputable file-sharing sites, torrent sites, or even legitimate websites that have been compromised can lead to infection.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to prevent infection by *.*[email protected]*.devon and other ransomware variants:

  • Regular Data Backups: Implement a robust 3-2-1 backup strategy (3 copies of data, 2 different media types, 1 offsite/cloud). Ensure backups are isolated from the network to prevent encryption.
  • Software and OS Updates: Keep your operating system, applications, and security software up-to-date with the latest patches. This fixes vulnerabilities that ransomware might exploit.
  • Reputable Antivirus/Anti-Malware Software: Install and maintain a high-quality antivirus/anti-malware solution with real-time protection and regularly updated definitions.
  • Email Security: Be extremely cautious with unsolicited emails. Avoid opening suspicious attachments or clicking links from unknown senders. Implement email filtering and spam protection.
  • Network Segmentation: Divide your network into segments to limit the lateral movement of ransomware if one part of the network is compromised.
  • Strong Passwords and Multi-Factor Authentication (MFA): Use strong, unique passwords for all accounts, especially for RDP and administrative access. Enable MFA wherever possible.
  • Disable RDP if Not Needed: If RDP is essential, secure it with strong passwords, network level authentication (NLA), and restrict access to trusted IPs only.
  • User Education: Train employees and users about phishing, social engineering, and safe browsing habits. Emphasize the dangers of downloading cracked software or files from untrusted sources.
  • Application Whitelisting: Restrict software execution to only approved applications. This can prevent unknown executables, like ransomware, from running.

2. Removal

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

  1. Isolate the Infected System: Immediately disconnect the infected computer from the network (unplug Ethernet cable, disable Wi-Fi) to prevent the ransomware from spreading to other devices.
  2. Identify and Terminate Malicious Processes:
    • Open Task Manager (Ctrl+Shift+Esc or Ctrl+Alt+Del -> Task Manager).
    • Look for suspicious processes with unusual names or high CPU/memory usage.
    • Research any suspicious process names before ending them.
  3. Boot into Safe Mode: Restart your computer and boot into Safe Mode with Networking. This loads only essential system services and can prevent the ransomware from fully executing.
  4. Scan and Remove:
    • Run a full system scan using your updated antivirus/anti-malware software.
    • Consider using a reputable second-opinion scanner (e.g., Malwarebytes, HitmanPro) to ensure thorough detection and removal.
  5. Clean Up Persistence Mechanisms:
    • Check startup folders (shell:startup) and registry keys (HKEYCURRENTUSER\Software\Microsoft\Windows\CurrentVersion\Run, HKEYLOCALMACHINE\Software\Microsoft\Windows\CurrentVersion\Run) for entries related to the ransomware.
    • Check Scheduled Tasks (taskschd.msc) for suspicious entries.
  6. Delete Ransomware Files: Once identified, delete all associated ransomware files. Be cautious, as some legitimate system files might be misidentified. Rely on your security software for this step.
  7. Change All Passwords: Change passwords for all accounts that may have been compromised or accessible from the infected system, especially those for online services, email, and network shares.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • Limited Decryption: For STOP/Djvu ransomware variants like .devon, free decryption is only possible if the encryption was performed using an offline key. Offline keys are used when the ransomware cannot establish a connection to its command-and-control server.
    • No Decryption for Online Keys: Unfortunately, most modern STOP/Djvu variants, including many .devon infections, use online keys. This means a unique encryption key is generated for each victim and transmitted to the attackers’ server. Without this specific online key (which the attackers hold), free decryption is currently not possible. Paying the ransom is strongly discouraged, as there’s no guarantee of receiving the decryptor, and it funds criminal activity.
  • Essential Tools/Patches:
    • Emsisoft Decryptor for STOP/Djvu Ransomware: This is the primary tool for attempts at free decryption. It can decrypt files encrypted with known offline keys. Download it from a trusted source like the Emsisoft website or No More Ransom project. The tool requires a pair of encrypted and original (unencrypted) files to try and identify the key. If an online key was used, this tool will indicate that decryption is currently not possible.
    • Data Recovery Software: Tools like PhotoRec or Recuva might be able to recover some original, unencrypted files if the ransomware deleted the originals before creating encrypted copies, or if the encryption process was interrupted. Success rates vary widely.
    • Shadow Volume Copies: Ransomware often attempts to delete Shadow Volume Copies (vssadmin delete shadows /all /quiet). If they were not deleted or were created after the infection, previous versions of files might be recoverable through Windows’ “Previous Versions” feature.
    • Cloud Backups/External Drives: The most reliable method of file recovery is restoring from clean, isolated backups.

4. Other Critical Information

  • Additional Precautions:
    • Ransom Note (_readme.txt): Like all STOP/Djvu variants, *.*[email protected]*.devon will drop a ransom note named _readme.txt (or similar variations) in every folder containing encrypted files. This note contains instructions for payment and the contact email ([email protected]).
    • HOSTS File Modification: STOP/Djvu often modifies the Windows HOSTS file (C:\Windows\System32\drivers\etc\hosts) to block access to security-related websites (e.g., antivirus vendors, security blogs) that might offer help or decryption tools. It’s crucial to check and clean this file after removal.
    • Info.txt/PersonalID.txt: The ransomware often creates info.txt or PersonalID.txt files containing a unique victim ID and sometimes the public key used for encryption. These files are sometimes crucial for decryption attempts using specialized tools.
  • Broader Impact:
    • Individual & Small Business Focus: STOP/Djvu ransomware predominantly targets individual users and small to medium-sized businesses due to its widespread distribution via pirated software and its less sophisticated, high-volume attack methods.
    • Emotional and Financial Distress: Victims often face significant emotional distress and potential financial losses due to data loss, recovery costs, or potential ransom payments.
    • Persistence: The continuous evolution and release of new variants by the STOP/Djvu operators demonstrate their resilience and persistence, making it a constant threat that requires ongoing vigilance.
    • Rise of Cryptocurrency Demands: Like many modern ransomware variants, *.*[email protected]*.devon demands payment in cryptocurrency (usually Bitcoin or Monero) due to its pseudonymous nature.

Combating *.*[email protected]*.devon effectively relies heavily on robust prevention, diligent removal, and a realistic understanding of decryption possibilities, emphasizing the critical role of external, isolated backups for true data recovery.