*[email protected]*.*random string*.crypto

[Content by Gemini 2.5]

This detailed resource is designed to provide comprehensive information about the ransomware variant identified by the file extension *[email protected]*.*random string*.crypto. This variant is part of the well-known and prolific Dharma ransomware family, specifically identified by the unique contact email address embedded in the file extension.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this ransomware variant is structured as .<random_string>.<[email protected]>.crypto. The random_string segment typically represents a unique victim ID or a short hexadecimal string.
  • Renaming Convention: When a file is encrypted by this Dharma variant, it follows a consistent renaming pattern:
    [original_filename].id-[victim_ID].[[email protected]].crypto
    For example, a file named document.docx might be renamed to document.docx.id-A1B2C3D4.[[email protected]].crypto. The original file extension is often preserved before the ransomware’s appended extensions. This pattern clearly indicates the ransomware’s presence and provides the attacker’s contact information.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The Dharma ransomware family has been active since at least 2016, undergoing continuous evolution and rebranding. Variants utilizing email addresses like [email protected] emerged more recently, with activity noted throughout 2023 and into 2024. While the Dharma family is persistent, specific contact email variants appear and disappear based on the affiliate groups using them. This particular [email protected] variant indicates a relatively current wave of attacks.

3. Primary Attack Vectors

Dharma ransomware, including the [email protected] variant, typically employs a range of common attack vectors, often focusing on vulnerable network services and social engineering:

  • Remote Desktop Protocol (RDP) Exploitation: This is the most common attack vector. Threat actors often scan for publicly exposed RDP ports, then use brute-force attacks or stolen credentials to gain unauthorized access. Once inside, they manually deploy the ransomware.
  • Phishing Campaigns: Malicious emails containing infected attachments (e.g., weaponized documents, executables disguised as legitimate files) or links to malicious websites are used to deliver the payload.
  • Exploiting Vulnerabilities: While less common for Dharma compared to RDP, it can exploit known software vulnerabilities in unpatched systems or applications to gain initial access.
  • Weak Credentials: Systems with weak or default passwords across various services (e.g., VPNs, web applications, databases) are susceptible to credential stuffing and dictionary attacks, leading to initial compromise.
  • Software Cracks/Pirated Software: Users downloading pirated software or “cracks” for legitimate programs often inadvertently execute the ransomware or other malware bundled within.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to prevent infection by Dharma ransomware:

  • Robust Backup Strategy: Implement a “3-2-1” backup rule: at least three copies of your data, stored on two different media types, with one copy off-site or air-gapped. Test backups regularly.
  • Secure RDP Access:
    • Disable RDP if not strictly necessary.
    • If RDP is required, place it behind a VPN.
    • Implement strong, complex passwords and Multi-Factor Authentication (MFA) for all RDP accounts.
    • Limit RDP access to specific trusted IP addresses.
    • Monitor RDP logs for unusual activity.
  • Patch Management: Regularly update operating systems, software, and firmware with the latest security patches to close known vulnerabilities.
  • Antivirus/Endpoint Detection and Response (EDR): Deploy and maintain reputable antivirus or EDR solutions with real-time protection and behavioral analysis capabilities. Keep definitions up-to-date.
  • Network Segmentation: Isolate critical systems and sensitive data from the rest of the network to limit lateral movement in case of a breach.
  • User Awareness Training: Educate employees about phishing, social engineering tactics, and the risks of opening suspicious attachments or clicking malicious links.
  • Principle of Least Privilege: Grant users and systems only the minimum necessary permissions to perform their tasks.

2. Removal

Once an infection is detected, follow these steps to remove the ransomware:

  • Immediate Isolation: Disconnect the infected system from the network (unplug Ethernet cable, disable Wi-Fi) to prevent further spread.
  • Identify & Terminate Processes: Use Task Manager (Windows) or process monitoring tools to identify and terminate suspicious processes associated with the ransomware. Look for newly created processes or unusually high CPU/disk usage.
  • Scan with Antivirus/Anti-Malware: Boot the system into Safe Mode with Networking (if possible) or use a bootable anti-malware scanner to perform a full system scan. Ensure your security software is fully updated.
  • Remove Persistence Mechanisms: Check common persistence locations (e.g., Registry Run keys, Startup folders, Scheduled Tasks) for entries created by the ransomware and remove them.
  • Delete Malicious Files: Manually delete any identified ransomware executables or associated files. Be cautious and verify before deleting system files.
  • Change All Passwords: After the system is deemed clean, change all passwords for accounts that may have been compromised, especially RDP credentials or network shares accessible from the infected machine.

3. File Decryption & Recovery

  • Recovery Feasibility: For the [email protected] Dharma variant, direct decryption without the attacker’s private key is generally NOT possible. Dharma ransomware employs strong, modern encryption algorithms (typically AES-256 for files and RSA-2048 for the AES key) making brute-forcing infeasible. While some older Dharma variants had decryption flaws, active versions like this one are robust.
    • No-More-Ransom Project: Always check the No More Ransom website (www.nomoreransom.org) for any potential decryptors. While they often have tools for older variants, newly emerged Dharma variants rarely have public decryptors available immediately.
    • Paying the Ransom: While paying is often the only way to potentially recover files without backups, it is strongly discouraged. There is no guarantee you will receive a decryptor, and it funds criminal activity, encouraging further attacks.
  • Essential Tools/Patches:
    • Anti-malware software: Reputable solutions like Malwarebytes, ESET, Bitdefender, or Kaspersky.
    • Operating System Patches: Ensure Windows Update is fully applied.
    • RDP Hardening Tools: Tools for monitoring RDP logs, IP blacklisting, or managing RDP access.
    • Backup & Recovery Software: Solutions for performing and restoring from backups.
    • File Recovery Software (data carving): In rare cases, for very recently encrypted files, tools like PhotoRec or Disk Drill might recover unencrypted remnants, but this is unlikely for fully encrypted files.

4. Other Critical Information

  • Additional Precautions: This [email protected] variant, like other Dharma strains, is known for its manual execution post-compromise. This means attackers often spend time exploring the network, escalating privileges, and identifying valuable targets before deploying the ransomware. Organizations should implement robust monitoring (SIEM/EDR) for suspicious activity like unauthorized RDP logins, privilege escalation attempts, or unusual file access patterns.
  • Broader Impact: The Dharma family, due to its low barrier to entry and prevalent use of RDP attacks, disproportionately affects small to medium-sized businesses (SMBs) and individual users who might have less sophisticated cybersecurity defenses. The [email protected] variant contributes to the significant financial and operational disruption caused by ransomware, leading to data loss, business downtime, reputational damage, and potentially regulatory fines. It highlights the critical need for fundamental cybersecurity hygiene, especially around remote access and patching.