*[email protected]*

[Content by Gemini 2.5]

The ransomware variant identified by the file extension *[email protected]* is a specific iteration of the Dharma (CrySiS/Phobos) ransomware family. This family has been prolific for several years, constantly evolving its final file extensions and attacker contact information (email addresses). The presence of [email protected] within the encrypted file’s name is a clear indicator of this particular campaign or actor utilizing the Dharma builder.

Here’s a detailed breakdown and recommended strategies:

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files encrypted by this variant will typically have a complex extension appended to their original name. The exact format often includes a unique victim ID, the attacker’s email address, and a final, variable extension. A common pattern observed for this specific variant is:
    .id-[8-hex-characters].[[email protected]].[final_extension]
    Where [8-hex-characters] is a unique hexadecimal string (e.g., AEF3B2C1) identifying the victim, and [final_extension] can be various strings like .wallet, .dharma, .bitcoin, .cezar, .adame, .bip, or other seemingly random combinations.

  • Renaming Convention: For example:

    • document.docx might become document.docx.id-AEF3B2C1.[[email protected]].wallet
    • photo.jpg might become photo.jpg.id-XYZ98765.[[email protected]].dharma
      The ransomware also typically drops ransom notes named INFO.txt and/or FILES ENCRYPTED.txt (or similar variations) in affected directories.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The Dharma ransomware family first emerged around 2016-2017. While the core Dharma code has been active since then, specific campaigns using email addresses like [email protected] tend to appear and disappear, often reflecting a particular threat actor’s activity period. This specific email address has been observed in campaigns predominantly since late 2020 and throughout 2021-2022, indicating a more recent wave of attacks utilizing this contact method.

3. Primary Attack Vectors

Dharma ransomware, including the [email protected] variant, commonly leverages the following propagation mechanisms:

  • Remote Desktop Protocol (RDP) Exploitation: This is the most prevalent method. Attackers scan for publicly exposed RDP ports, then use brute-force attacks or stolen credentials to gain unauthorized access to systems. Once inside, they manually deploy the ransomware.
  • Phishing Campaigns: Malicious emails containing infected attachments (e.g., seemingly legitimate documents with embedded macros) or links to malicious websites that deliver the ransomware payload.
  • Software Vulnerabilities: Exploiting known vulnerabilities in unpatched software or operating systems, although RDP exploitation remains significantly more common for Dharma.
  • Supply Chain Attacks: Less common for Dharma specifically, but possible if the ransomware is embedded within compromised legitimate software updates or third-party tools.
  • Drive-by Downloads/Malvertising: Users visiting compromised websites can unknowingly download the ransomware.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to defend against Dharma ransomware:

  • Secure RDP:
    • Disable RDP if not strictly necessary.
    • Use strong, unique passwords for all RDP accounts, ideally with a minimum of 15 characters, including a mix of uppercase, lowercase, numbers, and symbols.
    • Implement Multi-Factor Authentication (MFA) for all RDP access.
    • Restrict RDP access to trusted IP addresses only via firewall rules.
    • Place RDP behind a VPN for remote access, eliminating direct internet exposure.
    • Change the default RDP port (3389) to a non-standard, obscure port.
  • Regular Data Backups (3-2-1 Rule): Maintain at least three copies of your data, store two copies on different media, and keep one copy off-site and offline (air-gapped) to prevent ransomware from reaching them. Test your backup restoration process regularly.
  • Patch Management: Keep all operating systems, software, and applications updated with the latest security patches to close known vulnerabilities.
  • Endpoint Security: Deploy and maintain robust antivirus (AV) and Endpoint Detection and Response (EDR) solutions on all endpoints and servers. Ensure they are configured for real-time protection and regularly updated.
  • Network Segmentation: Isolate critical systems and sensitive data on separate network segments to limit lateral movement in case of a breach.
  • User Education: Train employees to recognize and report phishing attempts, suspicious emails, and malicious links.
  • Disable Macros by Default: Configure Microsoft Office and other productivity suites to disable macros by default, or only allow digitally signed macros from trusted sources.

2. Removal

If an infection is detected:

  1. Isolate the Infected System Immediately: Disconnect it from the network (unplug Ethernet cable, disable Wi-Fi) to prevent further spread.
  2. Identify and Terminate Malicious Processes: Use Task Manager or a process explorer tool to identify suspicious processes. Dharma often runs as a single executable or multiple processes; its names can vary.
  3. Boot into Safe Mode: This often prevents the ransomware from launching at startup.
  4. Perform a Full System Scan: Use a reputable, up-to-date antivirus/anti-malware suite (e.g., Malwarebytes, Bitdefender, ESET, etc.) to scan the entire system and remove identified threats. Multiple scans with different tools might be beneficial.
  5. Remove Ransom Notes: Once the ransomware executable is removed, delete any ransom notes (INFO.txt, FILES ENCRYPTED.txt, etc.) left behind.
  6. Check for Persistence Mechanisms: Look for suspicious entries in startup folders, registry keys (e.g., Run, RunOnce), or scheduled tasks that the ransomware might have created to maintain persistence.
  7. Change All Credentials: Assuming the RDP or other access points were compromised, immediately change passwords for all user accounts on the affected system, especially administrative accounts.

3. File Decryption & Recovery

  • Recovery Feasibility: Decryption of files encrypted by Dharma ransomware (including [email protected] variants) without paying the ransom is challenging and often not possible for recent variants.
    • No Universal Decryptor: There is no single, universal decryption tool for all Dharma variants because each encryption key is typically unique to the victim or campaign.
    • Limited Public Decryptors: While some older or poorly implemented Dharma variants might have had public decryptors released by security researchers (e.g., tools from Emsisoft or Kaspersky for specific older CrySiS/Dharma versions), new variants like those using [email protected] rarely have publicly available decryption tools immediately. Researchers continuously work to find vulnerabilities, but success is not guaranteed.
    • Paying the Ransom: Paying the ransom is strongly discouraged. There’s no guarantee the attackers will provide a working decryptor, and it funds future criminal activities.
  • Primary Recovery Method: Backups. The most reliable method to recover your files is to restore them from clean, uninfected backups that were created before the ransomware infection.
  • Essential Tools/Patches:
    • Antivirus/EDR Solutions: For ongoing protection and post-infection cleanup.
    • Operating System Patches: Ensure Windows Update is fully applied.
    • Backup and Recovery Software: Essential for implementing and managing your backup strategy.
    • Network Monitoring Tools: To detect unusual activity (e.g., RDP brute-force attempts).
    • Security Auditing Tools: To identify vulnerable configurations (e.g., exposed RDP ports, weak passwords).

4. Other Critical Information

  • Additional Precautions:
    • Data Exfiltration Risk: While Dharma is primarily focused on encryption, some variants or actors deploying it might also engage in data exfiltration (stealing data before encryption) for double extortion. Assume sensitive data may have been compromised.
    • Persistence: Dharma often establishes persistence on systems, making it crucial to thoroughly clean up all infection artifacts, not just the primary executable.
    • Targeting: Dharma frequently targets businesses and organizations, rather than just individual users, due to its RDP exploitation methods which are effective against servers and corporate networks.
  • Broader Impact:
    • Significant Financial Losses: Due to ransom demands, recovery costs (IT support, forensic analysis), and lost productivity.
    • Data Loss: If backups are not available or are also compromised.
    • Operational Disruption: Business operations can grind to a halt, leading to service outages and inability to serve customers.
    • Reputational Damage: Loss of customer trust if sensitive data is exfiltrated or services are severely disrupted.
    • Post-Incident Forensics: Critical for understanding how the breach occurred and implementing stronger defenses to prevent recurrence.

Combating *[email protected]* (and other Dharma variants) requires a multi-layered defense strategy, emphasizing robust preventative measures, swift incident response, and a reliable backup and recovery plan.