*id-***.jswrm

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This document provides a detailed technical breakdown and comprehensive recovery strategies for the ransomware variant identified by the file extension *id-***.jswrm. This variant is a part of the prolific STOP/Djvu ransomware family, known for its widespread distribution and evolving nature.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this variant is .jswrm.
  • Renaming Convention: *id-***.jswrm adheres to the typical STOP/Djvu renaming pattern. It appends a unique victim ID and the specific ransomware extension to the original filename.
    • Pattern: [original_filename].[id-[unique_victim_ID]].jswrm
    • Example: A file named document.docx would be renamed to document.docx.id-A1B2C3D4.jswrm.
    • The id-*** part represents a unique identifier generated for each victim. This ID is crucial as it determines whether an “online” or “offline” decryption key was used (more on this in the Decryption section).

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The STOP/Djvu ransomware family has been active since late 2018/early 2019 and continues to be one of the most prevalent ransomware threats. Specific variants like .jswrm emerge regularly as the operators update their codebase or distribution methods. While a precise “start date” for this exact .jswrm variant is difficult to pinpoint without specific threat intelligence reports, it signifies a recent addition to the long list of active Djvu variants.

3. Primary Attack Vectors

*id-***.jswrm primarily leverages common STOP/Djvu propagation mechanisms, which often rely on social engineering and deceptive practices:

  • Bundled Software & Cracked Programs: This is the most prevalent method. The ransomware is frequently distributed as a payload hidden within:
    • Cracked software installers: (e.g., cracked versions of popular games, software, and tools)
    • Keygens and software activators: Tools purporting to bypass license checks.
    • Fake software updates or installers: Masquerading as legitimate software from untrustworthy sources.
    • Freeware and shareware bundles: Downloaded from illicit or less reputable file-sharing websites.
  • Malicious Downloads: Downloads from compromised websites, malicious advertisements (malvertising), or drive-by downloads.
  • Phishing Campaigns (Less Common for Djvu): While less typical for Djvu compared to other ransomware families, email attachments or links pointing to malicious downloads can also be used.
  • Software Vulnerabilities: While Djvu typically doesn’t directly exploit critical vulnerabilities like EternalBlue or RDP flaws for initial infection, a compromised system (e.g., via a pre-existing vulnerability exploited by another threat) could lead to Djvu being deployed as a secondary payload. However, direct mass exploitation through unpatched systems is not its primary modus operandi.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are the most effective defense against *id-***.jswrm and similar ransomware threats:

  • Robust Backup Strategy: Implement and regularly test a 3-2-1 backup rule (3 copies of data, 2 different media types, 1 copy offsite/offline). Offline and immutable backups are crucial for ransomware recovery.
  • Software and OS Updates: Keep your operating system, applications, and security software fully patched and updated to close known security vulnerabilities.
  • Reputable Antivirus/Endpoint Detection and Response (EDR): Use high-quality, up-to-date antivirus or EDR solutions with real-time protection and behavioral analysis capabilities.
  • User Awareness Training: Educate users about the dangers of downloading pirated software, clicking on suspicious links, opening unexpected attachments, and general social engineering tactics.
  • Network Security:
    • Implement firewalls and intrusion prevention systems.
    • Use strong, unique passwords for all accounts.
    • Disable Remote Desktop Protocol (RDP) if not essential, and secure it with strong passwords, MFA, and IP whitelisting if in use.
    • Segment networks to limit lateral movement in case of a breach.
  • Application Whitelisting: Allow only approved applications to run, preventing unauthorized executables (like ransomware) from launching.

2. Removal

Once an infection is detected, follow these steps to remove *id-***.jswrm:

  1. Isolate the Infected System: Immediately disconnect the infected computer from the network (unplug Ethernet cable, disable Wi-Fi) to prevent the ransomware from spreading to other devices.
  2. Identify and Terminate Processes: Use Task Manager (Windows) to identify any suspicious processes. While *id-***.jswrm may have completed its encryption, it’s good practice to ensure no malicious processes are still running.
  3. Boot into Safe Mode (Optional but Recommended): Restart the computer and boot into Safe Mode with Networking. This often prevents the ransomware from launching fully, making it easier for security software to operate.
  4. Scan and Remove with Anti-Malware:
    • Use a reputable anti-malware solution (e.g., Malwarebytes, SpyHunter, Kaspersky, ESET, Bitdefender) to perform a full system scan. Ensure the security software is fully updated.
    • Remove all detected threats, including the ransomware executable, associated persistence mechanisms (e.g., registry entries, scheduled tasks), and any dropped files.
  5. Check for Persistence Mechanisms:
    • Review msconfig (Startup tab), Task Scheduler, and Registry Editor (HKCU\Software\Microsoft\Windows\CurrentVersion\Run, HKLM\Software\Microsoft\Windows\CurrentVersion\Run) for suspicious entries.
    • *id-***.jswrm often modifies the Windows hosts file to block access to security-related websites, preventing victims from downloading antivirus tools or seeking help. Check %SystemRoot%\System32\drivers\etc\hosts and remove any entries blocking security sites.
  6. Remove Shadow Copies: *id-***.jswrm typically attempts to delete Volume Shadow Copies using commands like vssadmin.exe Delete Shadows /All /Quiet. However, it’s good practice to verify and ensure no lingering shadow copies (legitimate or otherwise) exist that could be re-infected.

3. File Decryption & Recovery

The feasibility of decrypting files encrypted by *id-***.jswrm varies significantly:

  • Recovery Feasibility:
    • Online Keys (Most Common): If the ransomware successfully communicates with its command-and-control (C2) server, it generates a unique “online” key for each victim. In this scenario, decryption is virtually impossible without the attacker’s private key. The Emsisoft Decryptor (see below) cannot decrypt files encrypted with online keys unless the specific key is somehow acquired by researchers.
    • Offline Keys (Less Common, but Possible): If the ransomware fails to connect to its C2 server (e.g., due to network issues, firewall, or server downtime), it uses a pre-generated “offline” key from its local resources. If this specific offline key is later discovered by security researchers (by analyzing numerous samples), the Emsisoft Decryptor might be able to decrypt files. The success depends on the id-*** identifying a known offline key.
    • Paying the Ransom: It is strongly advised against paying the ransom. There is no guarantee you will receive a working decryptor, and it encourages further ransomware attacks.
  • Essential Tools/Patches:
    • Emsisoft Decryptor for STOP/Djvu: This is the primary tool for attempts at decrypting STOP/Djvu files. Download it from the official Emsisoft website.
      • Usage: The tool attempts to match your victim ID to known offline keys. It requires a pair of encrypted and original files (if available) to aid in the process, but often relies on matching the victim ID found in the .jswrm extension to its database of keys.
      • Limitations: As explained, it primarily works for offline keys discovered by researchers.
    • Data Recovery Software: Tools like PhotoRec, R-Studio, or EaseUS Data Recovery Wizard can sometimes recover previous versions or fragments of files that were not fully overwritten by the ransomware. Success rates are generally low, as ransomware often overwrites files completely.
    • System Restore/Shadow Copies: While Djvu variants typically delete Volume Shadow Copies, always check if previous versions of files or System Restore Points are available. Right-click a file/folder -> “Restore previous versions.”
    • Cloud/External Backups: The most reliable method is to restore from uninfected, recent backups stored on external drives or cloud services that were not accessible to the ransomware.

4. Other Critical Information

  • Additional Precautions (InfoStealer Component): A critical distinguishing characteristic of many STOP/Djvu variants, including those using the .jswrm extension, is the installation of an info-stealing malware (e.g., Vidar, Azorult, RedLine Stealer) alongside the ransomware. This means that before your files were encrypted, your system likely had its sensitive data exfiltrated.
    • Immediate Actions Required:
      • Change All Passwords: Assume all passwords stored in web browsers, password managers, and used for online services (email, banking, social media, crypto exchanges) have been compromised. Change them immediately from a clean device.
      • Monitor Financial Accounts: Keep a close watch on bank accounts, credit cards, and cryptocurrency wallets for any unauthorized activity.
      • Alert Contacts: Be wary of phishing attempts targeting your contacts, as your email account details might have been stolen.
      • Two-Factor Authentication (2FA/MFA): Enable 2FA/MFA on all critical accounts where available.
  • Ransom Note: *id-***.jswrm will typically drop a ransom note named _readme.txt in every folder containing encrypted files, and on the desktop. This note provides instructions on how to contact the attackers (usually via email) and the ransom amount.
  • Broader Impact:
    • Data Loss & Disruption: Significant loss of data for individuals and operational disruption for organizations.
    • Financial Cost: Beyond the potential ransom (which should be avoided), there are costs associated with downtime, recovery efforts, IT security consulting, and potential legal/compliance repercussions.
    • Identity Theft & Fraud: The info-stealing component elevates the risk to identity theft and various forms of financial fraud, leading to long-term consequences.
    • Reputational Damage: For businesses, a ransomware attack can severely damage reputation and customer trust.

By understanding the technical nuances and implementing robust prevention and recovery strategies, individuals and organizations can significantly mitigate the impact of *id-***.jswrm and similar ransomware threats.