*[email protected]*

[Content by Gemini 2.5]

The ransomware variant identified by the file extension *[email protected]* is a typical example of a Dharma ransomware (also known as CrySiS/Dharma) variant. Dharma is a persistent and evolving ransomware family that has been active for several years. The *[email protected]* part indicates the specific contact email chosen by the attackers for that particular campaign, which is appended to the encrypted files.

Here’s a detailed breakdown:

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files encrypted by this variant will typically have an extension appended to their original name that includes a unique victim ID, the attacker’s email address, and often a final, specific ransomware extension. While the prompt identifies it by *[email protected]*, this is primarily the attacker’s contact email embedded within the full extension.

  • Renaming Convention: The typical renaming pattern follows this structure:
    [original_filename].[original_extension].[id-<victim_id>].[[email protected]].<new_ransomware_extension>

    Example:

    • A file named document.docx might become document.docx.id-A1B2C3D4.[[email protected]].pingy or document.docx.id-A1B2C3D4.[[email protected]].btc or document.docx.id-A1B2C3D4.[[email protected]].wallet.
    • The final <new_ransomware_extension> (e.g., .pingy, .btc, .wallet) can vary with different Dharma campaigns, but the embedded email [email protected] remains consistent for this specific variant.
    • A ransom note, typically named FILES ENCRYPTED.txt, info.txt, HOW TO DECRYPT YOUR FILES.txt, or README.txt, will be dropped in every folder containing encrypted files.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The Dharma ransomware family has been active since at least 2016. Variants using various email addresses (including those from domains like @india.com, @aol.com, @gmail.com, etc.) have emerged consistently over the years. Specific campaigns using [email protected] as the contact address would fall within this broader timeline, appearing as new iterations or attack waves. It’s not a single, isolated outbreak, but rather a persistent threat from an evolving ransomware family.

3. Primary Attack Vectors

*[email protected]* (as a Dharma variant) primarily leverages the following attack vectors:

  • Remote Desktop Protocol (RDP) Exploitation: This is the most common and preferred method. Attackers scan the internet for systems with RDP exposed to the public internet, then attempt to:
    • Brute-force weak RDP credentials: Using automated tools to guess usernames and passwords.
    • Exploit compromised RDP credentials: If they have acquired valid login details through other means (e.g., dark web marketplaces, infostealers, previous breaches).
  • Phishing Campaigns: While less common than RDP for Dharma, targeted phishing emails can be used to deliver the ransomware, often disguised as legitimate documents (e.g., invoices, shipping notifications) with malicious attachments or links.
  • Software Vulnerabilities: Exploitation of unpatched vulnerabilities in public-facing applications (e.g., web servers, content management systems) can provide initial access, allowing attackers to then deploy ransomware.
  • Supply Chain Attacks: In some cases, Dharma variants have been distributed through compromised legitimate software updates or third-party tools.
  • Malicious Downloads/Cracked Software: Users downloading pirated software, cracked utilities, or malicious executables from untrusted sources inadvertently infect their systems.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to avoid infection:

  • Regular Data Backups: Implement a robust 3-2-1 backup strategy (3 copies of data, on 2 different media, with 1 copy offsite/offline). Test backups regularly to ensure restorability.
  • Strong RDP Security:
    • Disable RDP entirely if not strictly necessary.
    • If RDP is required, place it behind a VPN or bastion host.
    • Use strong, unique passwords and Multi-Factor Authentication (MFA) for all RDP accounts.
    • Limit RDP access to specific IP addresses via firewall rules.
    • Monitor RDP logs for unusual activity or brute-force attempts.
  • Patch Management: Keep operating systems, software, and firmware updated with the latest security patches. This is critical for closing known vulnerabilities that ransomware might exploit.
  • Antivirus/Endpoint Detection & Response (EDR): Deploy and maintain reputable antivirus and EDR solutions on all endpoints and servers. Ensure they are up-to-date and configured for real-time protection.
  • Network Segmentation: Isolate critical systems and sensitive data from the rest of the network to limit the lateral movement of ransomware in case of a breach.
  • Email Security: Implement robust email filtering, spam protection, and sandboxing to block malicious attachments and links.
  • User Education: Train employees to recognize and report phishing attempts, avoid clicking suspicious links, and be cautious about opening unsolicited attachments.
  • Disable SMBv1: Ensure Server Message Block version 1 (SMBv1) is disabled, as it has known vulnerabilities exploited by many ransomware variants for lateral movement.
  • Principle of Least Privilege: Grant users and applications only the minimum necessary permissions to perform their tasks.

2. Removal

If a system is infected, follow these steps for cleanup:

  1. Isolate the Infected System: Immediately disconnect the compromised computer or server from the network to prevent further spread.
  2. Identify and Terminate Ransomware Processes: Use Task Manager (Windows) or process monitoring tools to identify suspicious processes. Dharma often runs with obfuscated names or legitimate-sounding names.
  3. Scan with Antivirus/Anti-Malware: Boot the system into Safe Mode with Networking (if possible) or use a bootable anti-malware rescue disk to perform a full system scan. Reputable tools like Malwarebytes, ESET, or Microsoft Defender (updated) can help detect and remove the ransomware executable.
  4. Remove Persistence Mechanisms: Check common persistence locations for malicious entries:
    • Registry Editor (regedit.exe): Look under HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run, HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run, and similar keys.
    • Task Scheduler (taskschd.msc): Review scheduled tasks for any suspicious entries designed to launch the ransomware.
    • Startup Folders: Check shell:startup and shell:common startup.
    • Services (services.msc): Look for newly created or modified services.
  5. Restore from Clean Backup: Once the ransomware is confirmed removed, the only reliable way to recover encrypted files is to restore from a clean, uninfected backup.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • For Dharma ransomware variants, including those using the *[email protected]* email, decryption without the attacker’s private key is generally NOT possible for recent versions.
    • While Emsisoft and No More Ransom have released decryptors for some older Dharma variants, new variants with different encryption keys or implementations are often not covered. The *[email protected]* variant is likely one for which a public decryptor is unavailable.
    • Paying the ransom is strongly discouraged. There is no guarantee you will receive a decryptor, it funds future criminal activity, and the decryptor might not work perfectly, potentially corrupting files further.
  • Methods/Tools Available (Limited for this specific variant):
    • Emsisoft Decryptor for Dharma: Check the Emsisoft Ransomware Decryption Tools page (search for Dharma) and the No More Ransom! project website. However, it is highly unlikely they will have a specific decryptor for the *[email protected]* variant.
    • Shadow Volume Copies (VSS): Ransomware often attempts to delete these. Try using tools like vssadmin (from an elevated command prompt) or ShadowExplorer to check for previous versions of files. If not deleted, this might offer a limited recovery option for some files.
    • Data Recovery Software: Tools like PhotoRec or Recuva might be able to recover some deleted original files (before encryption and deletion by the ransomware), but success rates vary greatly.
  • Essential Tools/Patches:
    • Updated Antivirus/EDR: For detection and removal.
    • Operating System Patches: To close vulnerabilities.
    • Backup Software: Critical for recovery.
    • Network Monitoring Tools: To detect suspicious activity and lateral movement.
    • RDP Security Tools: For hardening RDP access.

4. Other Critical Information

  • Additional Precautions:
    • User Account Control (UAC): Ensure UAC is enabled and configured correctly to prompt for administrative privileges.
    • Software Restriction Policies/AppLocker: Implement policies to prevent execution of unauthorized software, especially from common user-writable locations like %TEMP% or %APPDATA%.
    • Regular Security Audits: Perform regular vulnerability scans and penetration tests to identify and remediate weaknesses.
    • Offline Backups: Ensure that at least one copy of your backups is stored offline and off-network, making it inaccessible to ransomware.
  • Broader Impact:
    • Significant Data Loss: The primary and most devastating impact for victims who do not have adequate backups.
    • Operational Disruption: Business operations can be severely crippled or halted, leading to lost revenue and productivity.
    • Financial Costs: Beyond the potential ransom payment (which should be avoided), there are costs associated with system remediation, data recovery efforts, potential legal fees, and reputational damage.
    • Reputational Damage: For businesses, a ransomware attack can severely damage customer trust and brand reputation.
    • Supply Chain Risk: If an organization in a supply chain is hit, it can disrupt operations for interconnected businesses.

In conclusion, combating the *[email protected]* ransomware variant, like most Dharma variants, heavily relies on robust prevention strategies and maintaining consistent, tested backups. Decryption without the attacker’s key is generally not feasible, making prevention and recovery from backups the only reliable path to mitigation.