*[email protected]*

[Content by Gemini 2.5]

This document provides a comprehensive overview of the ransomware variant identified by the file extension *[email protected]*, offering both a technical breakdown and practical recovery strategies. It is crucial to understand that this specific extension often points to a variant of a well-established ransomware family, most commonly Dharma (also known as Dharma/Phobos variants), which utilizes the contact email address [email protected] for ransom negotiations.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this ransomware is not simply *[email protected]*. Instead, [email protected] is the contact email address embedded within the full file extension appended to encrypted files. The typical pattern observed is:
  • Renaming Convention: Encrypted files are renamed by appending this complex extension to their original filename. The original filename and extension are usually preserved, followed by a unique victim ID (often hexadecimal or alphanumeric), a short random string, and then the [email protected] contact identifier.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Variants of Dharma ransomware incorporating various email addresses have been active since at least 2016. The specific *[email protected]* contact email began to appear and gain prominence in ransomware incidents primarily starting in late 2023 and continuing into 2024. This indicates a newer wave or specific campaign utilizing this contact.

3. Primary Attack Vectors

This variant, like many Dharma/Phobos iterations, commonly employs a range of propagation mechanisms, often indicative of human-operated ransomware rather than purely automated worms:

  • Remote Desktop Protocol (RDP) Exploitation: This is the most prevalent attack vector. Threat actors scan for publicly exposed RDP ports, then use brute-force attacks or stolen credentials to gain unauthorized access to victim systems. Once inside, they manually deploy the ransomware.
  • Phishing Campaigns: Malicious emails are used to deliver the ransomware payload. These emails may contain:
    • Malicious Attachments: Such as seemingly legitimate documents (e.g., invoices, shipping notifications) embedded with macros or containing executable files (e.g., .exe, .js, .vbs) disguised as other file types.
    • Malicious Links: Redirecting users to compromised websites that host the ransomware or exploit kits.
  • Software Vulnerabilities: While less common than RDP for this specific variant, exploitation of known vulnerabilities in unpatched software (especially those publicly exposed like VPNs, web servers, or content management systems) can be used to gain initial access.
  • Weak Credentials/Credential Stuffing: Compromised credentials obtained from other breaches or weak password practices can be used to access various services, not just RDP.
  • Cracked Software/Malicious Downloads: Users downloading pirated software, keygens, or unofficial patches from untrusted sources may inadvertently execute the ransomware.

Remediation & Recovery Strategies:

1. Prevention

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

  • Strong RDP Security:
    • Disable RDP entirely if not strictly necessary.
    • If RDP is required, restrict access to whitelisted IP addresses via firewall rules.
    • Enforce strong, unique passwords for all RDP accounts.
    • Implement Multi-Factor Authentication (MFA) for RDP access.
    • Place RDP behind a VPN.
    • Monitor RDP logs for unusual activity or failed login attempts.
  • Regular, Offline Backups: Implement a 3-2-1 backup strategy (3 copies of data, 2 different media types, 1 copy offsite/offline/immutable). Ensure backups are isolated from the network to prevent encryption.
  • Patch Management: Regularly update operating systems, software, and firmware to patch known vulnerabilities that attackers could exploit. Prioritize critical security updates.
  • Endpoint Protection: Deploy and maintain robust Endpoint Detection and Response (EDR) solutions or next-generation antivirus (NGAV) that can detect and prevent ransomware behaviors.
  • Email Security: Implement advanced email filtering solutions, user awareness training to identify phishing attempts, and disable macro execution by default in Microsoft Office applications.
  • Network Segmentation: Divide your network into smaller, isolated segments to limit lateral movement of ransomware if one segment is compromised.
  • Principle of Least Privilege: Ensure users and applications only have the minimum necessary permissions to perform their functions.

2. Removal

If an infection occurs, follow these steps for effective cleanup:

  • Isolate Infected Systems: Immediately disconnect affected computers from the network (unplug network cables, disable Wi-Fi) to prevent further spread.
  • Identify & Kill Malicious Processes: Use Task Manager, Process Explorer, or command-line tools (e.g., tasklist, taskkill) to identify and terminate suspicious processes. Look for processes running from unusual locations or with high CPU/disk usage.
  • Full System Scan: Boot the isolated system into Safe Mode or use a rescue disk to run a full scan with an updated, reputable antivirus/anti-malmalware solution. Ensure the antivirus definitions are up-to-date.
  • Remove Persistence Mechanisms: Check common persistence locations for malicious entries, including:
    • Startup folders (shell:startup, shell:common startup)
    • Registry Run keys (HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run)
    • Scheduled Tasks (schtasks)
    • WMI Event Consumers.
  • Change All Credentials: Assume that credentials on the infected network might be compromised. Force a password reset for all users, especially administrators and service accounts, after cleaning the network.
  • Investigate Root Cause: Determine how the ransomware entered the system (e.g., RDP brute-force, phishing) to address the vulnerability and prevent future attacks.

3. File Decryption & Recovery

  • Recovery Feasibility: For files encrypted by the *[email protected]* variant (Dharma/Phobos), free decryption is generally NOT possible. These ransomware families typically use strong, military-grade encryption algorithms (like AES-256 and RSA-2048) with unique keys generated for each victim. Unless the attackers make a mistake and leak their master keys (which is rare), or a flaw is found in their encryption implementation, there are no public decryptors available.
    • NEVER pay the ransom. Paying incentivizes attackers, provides no guarantee of decryption, and there’s a risk your data won’t be recovered or that you’ll be targeted again.
  • Essential Tools/Patches:
    • Backups: The primary and most reliable method for file recovery is restoring from clean, recent backups.
    • Windows Shadow Copies (Volume Shadow Copy Service): While ransomware often attempts to delete shadow copies, sometimes older ones may survive. Tools like vssadmin (command line) or ShadowExplorer (GUI) can be used to check for and restore previous versions of files. This is a last resort and often not successful.
    • Data Recovery Software: In some rare cases, if the ransomware merely copies and encrypts files, then deletes the originals, data recovery software might recover some original, unencrypted files from free space. This is highly unreliable for ransomware infections.
    • Microsoft Security Updates: Keep your Windows OS fully patched.
    • Reputable Antivirus/EDR: Ensure your security software is up-to-date.
    • Firewall: Properly configured firewalls are crucial for restricting RDP access and preventing unauthorized inbound connections.

4. Other Critical Information

  • Additional Precautions:
    • Human-Operated Ransomware: The *[email protected]* variant often falls under the category of human-operated ransomware. This means attackers gain initial access (e.g., via RDP), then manually explore the network, elevate privileges, disable security software, and prepare for the ransomware deployment. This reconnaissance phase can last days or weeks.
    • Double Extortion Risk (Lower for this variant): While some advanced ransomware groups engage in double extortion (exfiltrating data before encryption and threatening to leak it), Dharma/Phobos variants using email contacts like *[email protected]* typically focus primarily on encryption for ransom. However, data exfiltration is always a possibility and should be assumed until proven otherwise.
    • Ransom Notes: The ransomware typically drops text files named FILES ENCRYPTED.txt, info.txt, or similar, containing instructions on how to contact the attackers (via [email protected] or sometimes a TOX ID) for decryption keys.
  • Broader Impact:
    • Significant Business Disruption: Beyond data loss, organizations often face severe operational paralysis, loss of productivity, and extended downtime.
    • Financial Costs: Includes direct ransom demands (though not recommended to pay), costs associated with incident response, system remediation, data recovery, and potential reputational damage.
    • Supply Chain Risk: If an organization within a supply chain is affected, it can have cascading effects on partners and customers.
    • Legal and Compliance Ramifications: Depending on the industry and data involved, ransomware incidents can trigger reporting requirements under regulations like GDPR, HIPAA, or various state privacy laws, potentially leading to fines or legal action.

By understanding the technical aspects and implementing robust prevention and recovery strategies, organizations and individuals can significantly reduce their risk of falling victim to the *[email protected]* ransomware variant.