*[email protected]*.adobe

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This document provides a comprehensive analysis and actionable strategies against the ransomware variant identified by the file extension *[email protected]*.adobe. This particular variant is characteristic of the Dharma ransomware family, which has seen numerous iterations over the years, often distinguished by the email address and custom extension appended to encrypted files.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The ransomware appends an additional file extension, typically in the format .id-[victim_ID].[email_address].extension. For this specific variant, the pattern would be .[victim_ID][email protected].
  • Renaming Convention: When a file is encrypted by this variant, its original name is modified to include a unique victim ID, the attacker’s specified email address, and the new .adobe extension.
    • Example: A file named document.docx would be renamed to something like [email protected].
    • The id-A1B2C3D4 portion is a unique identifier generated for each victim, making it challenging to create a universal decryptor without the attacker’s specific key.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Variants using the *[email protected]*.adobe extension, falling under the broader Dharma ransomware family, have been actively observed since late 2018 or early 2019, with the Dharma family itself being prominent since 2016-2017. New variants and specific extension patterns are continually emerging as the threat actors evolve their tactics. This specific [email protected] email address has been consistently linked to various Dharma attacks over time.

3. Primary Attack Vectors

Dharma ransomware, including variants like *[email protected]*.adobe, primarily utilizes a few common, yet effective, propagation mechanisms:

  • Remote Desktop Protocol (RDP) Exploitation: This is the most prevalent attack vector. Attackers scan for publicly exposed RDP ports (typically 3389) with weak or default credentials, or brute-force passwords until they gain access. Once inside, they manually deploy the ransomware.
  • Phishing Campaigns: Malicious emails containing weaponized attachments (e.g., seemingly legitimate documents with embedded macros, or archives containing executable files) or links to malicious websites are used to trick users into executing the ransomware.
  • Software Vulnerabilities & Exploits: While less common than RDP, the ransomware can exploit unpatched vulnerabilities in public-facing applications (e.g., VPN appliances, web servers, content management systems) to gain initial access.
  • Supply Chain Attacks: In some instances, the ransomware might be delivered through compromised software updates or legitimate software downloaded from infected third-party sites.
  • Drive-by Downloads/Malvertising: Users might unknowingly download the ransomware by visiting compromised websites or interacting with malicious advertisements.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to defend against *[email protected]*.adobe and similar ransomware variants:

  • Strong RDP Security:
    • Disable RDP if not absolutely necessary.
    • If RDP is required, place it behind a VPN.
    • Enforce 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 (failed login attempts, connections from unexpected IPs).
  • Regular Backups: Implement a robust 3-2-1 backup strategy (3 copies of data, on 2 different media, with 1 copy off-site/offline). Test your backup recovery process regularly. Offline backups are critical for ransomware recovery.
  • Patch Management: Keep all operating systems, software, and firmware up-to-date with the latest security patches. Pay particular attention to browsers, email clients, office suites, and network services.
  • Endpoint Detection and Response (EDR) / Antivirus (AV): Deploy and maintain reputable EDR/AV solutions with real-time protection and behavioral analysis capabilities. Ensure signatures are always 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, suspicious emails, and safe browsing habits. Conduct simulated phishing exercises regularly.
  • Least Privilege Principle: Grant users and applications only the minimum necessary permissions to perform their tasks.
  • Disable Unnecessary Services: Turn off any services or ports that are not actively used.

2. Removal

Infection cleanup requires careful and methodical steps to prevent reinfection:

  • Isolate Infected Systems: Immediately disconnect affected computers from the network (unplug Ethernet cables, disable Wi-Fi) to prevent further spread.
  • Identify and Quarantine: Use a reputable antivirus or anti-malware solution (e.g., Malwarebytes, Emsisoft, your existing EDR solution) to scan the isolated system. Ensure the software is updated with the latest definitions.
  • Boot into Safe Mode: If possible, boot the infected system into Safe Mode with Networking (or Safe Mode without Networking if network access is not needed for tool downloads) to prevent the ransomware from running automatically.
  • Terminate Malicious Processes: Use Task Manager or a process explorer tool (e.g., Sysinternals Process Explorer) to identify and terminate any suspicious processes. Dharma often disguises itself as legitimate system processes.
  • Remove Persistence Mechanisms: Check common persistence locations for malicious entries:
    • Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run, HKLM\Software\Microsoft\Windows\CurrentVersion\Run)
    • Startup folders
    • Scheduled Tasks
    • Services
  • Delete Malicious Files: Remove all identified ransomware executable files and associated dropped files (e.g., the ransom note, often named FILES ENCRYPTED.txt, info.txt, _README.txt, or similar). Be cautious not to delete legitimate system files.
  • Reinstall Operating System (Recommended): For critical systems or widespread infections, a clean reinstallation of the operating system is the most secure and recommended approach to ensure complete removal and eliminate any potential backdoors left by the attackers.
  • Review Logs: After initial cleanup, review system logs (Event Viewer, security logs) for signs of lateral movement, privilege escalation, or other attacker activity.

3. File Decryption & Recovery

  • Recovery Feasibility: For most recent Dharma variants, including those using the *[email protected]*.adobe extension, decryption without the attacker’s key is generally not possible. The encryption algorithm used (typically AES-256 combined with RSA-2048) is robust, and each victim receives a unique encryption key, which is then encrypted with the attacker’s public key.

    • Exceptions: Very old Dharma variants might have vulnerabilities that allowed for free decryptors to be developed (e.g., by Emsisoft). However, these are rare and typically do not apply to newer, constantly evolving variants like the one specified.
    • Recommendation: Do NOT pay the ransom. There is no guarantee you will receive a working decryptor, and it funds criminal activity.

  • Methods/Tools Available (Limited):

    • Emsisoft Decryptor for Dharma: While specific for older variants, it’s always worth trying the Emsisoft Decryptor for Dharma, as it covers multiple known variants. However, expect it not to work for the *[email protected]*.adobe variant.
    • Data Recovery Software: Sometimes, data recovery software can retrieve previous versions of files or shadow copies (Volume Shadow Copies Service – VSS) if they were not successfully deleted by the ransomware. However, most modern ransomware variants specifically target and delete shadow copies.
    • Backups: The most reliable method for file recovery is restoring from clean, verified backups made prior to the infection.

  • Essential Tools/Patches:

    • Anti-malware/EDR Solutions: Emsisoft, Malwarebytes, Sophos, CrowdStrike, SentinelOne (for detection, removal, and ongoing protection).
    • Backup Solutions: Veeam, Acronis, Carbonite, cloud backup services.
    • Patch Management Tools: Windows Server Update Services (WSUS), SCCM, or third-party patch management solutions.
    • Network Monitoring Tools: For detecting unusual RDP activity or outbound connections.
    • Firewall: Properly configured network and host-based firewalls.

4. Other Critical Information

  • Additional Precautions:
    • Disable VSS (Volume Shadow Copy Service) Deletion: While ransomware often attempts to delete VSS copies, having a policy to limit VSS deletion by unauthorized processes might offer a slim chance of recovery for some files. However, this is not a primary defense.
    • Application Whitelisting: Implement application whitelisting to prevent unauthorized executables (like ransomware) from running on your systems.
    • Regular Security Audits: Conduct regular penetration tests and vulnerability assessments to identify and remediate weaknesses.
  • Broader Impact:
    • Business Disruption: Dharma variants, including *[email protected]*.adobe, frequently target businesses and organizations, leading to significant downtime, operational paralysis, and substantial financial losses due to lost productivity, recovery costs, and potential data loss.
    • Data Exfiltration (Possible but Less Common): While Dharma’s primary goal is encryption for ransom, some variants of ransomware (not specifically tied to Dharma by default, but a general trend) also engage in data exfiltration (stealing data) before encryption to enable double extortion tactics. Always assume data compromise.
    • Reputational Damage: Organizations that suffer ransomware attacks often face severe reputational damage, leading to loss of customer trust and potential legal ramifications.
    • Evolution of Tactics: The *[email protected]*.adobe variant highlights the constant evolution of ransomware. Threat actors quickly adapt, changing their email addresses, added extensions, and sometimes even their underlying code to evade detection and complicate recovery efforts. This necessitates a proactive and adaptive cybersecurity posture.

By adhering to these technical insights and implementing robust prevention, removal, and recovery strategies, individuals and organizations can significantly mitigate the risk and impact of the *[email protected]*.adobe ransomware variant.