*id62133703*

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This document provides a comprehensive overview of the ransomware variant identified by the file extension *id62133703*. Based on its characteristic naming convention (id followed by numbers), this variant is strongly suspected to be part of the pervasive Djvu/STOP ransomware family, which continuously releases new iterations. While the exact numerical string 62133703 uniquely identifies this specific variant’s extension, the underlying mechanics and recommended recovery strategies largely align with those for the broader Djvu/STOP family.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files encrypted by this ransomware variant will have *id62133703* appended as their new extension. For example, document.docx would become document.docx.id62133703, and picture.jpg would become picture.jpg.id62133703.
  • Renaming Convention: The ransomware typically appends *id62133703* directly to the original file name, preserving the original extension. It does not usually rename the base filename. In addition to encrypting files, the ransomware creates a ransom note file, commonly named _readme.txt, in every folder where encryption has occurred. This note contains instructions for the victim on how to pay the ransom to decrypt their files.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The Djvu/STOP ransomware family, of which *id62133703* is a probable variant, has been continuously active and evolving since late 2018. New variants with unique extensions like *id62133703* emerge frequently, sometimes on a daily or weekly basis. Therefore, *id62133703* would represent one of the more recent additions to this ongoing threat landscape, rather than a single, isolated outbreak.

3. Primary Attack Vectors

  • Propagation Mechanisms: Djvu/STOP ransomware, including the *id62133703* variant, primarily propagates through deceptive and socially engineered methods rather than exploiting network vulnerabilities (like EternalBlue or SMBv1). Common attack vectors include:
    • Cracked Software/Pirated Content: Distribution through torrent sites, warez forums, and unofficial download portals where users seek “cracked” versions of popular software (e.g., Adobe Photoshop, Microsoft Office, various games). The ransomware is bundled within these seemingly legitimate installers.
    • Fake Software Updates: Websites or pop-ups prompting users to install urgent “updates” for web browsers, Flash Player, or other common software, which are actually disguised ransomware installers.
    • Malicious Advertisements (Malvertising): Advertisements on legitimate websites that redirect users to malicious landing pages or initiate drive-by downloads.
    • Bundled Software: Download managers or freeware installers that secretly bundle the ransomware with other, seemingly harmless applications.
    • Phishing/Spam Campaigns: Less common for Djvu/STOP, but still a possibility, where malicious attachments or links in emails lead to infection.
    • Remote Desktop Protocol (RDP) Exploits: While not a primary method, poorly secured RDP endpoints can be targeted for manual deployment of this or other ransomware.

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
    • Regular Backups: Implement a robust 3-2-1 backup strategy (3 copies, 2 different media, 1 offsite/cloud). Ensure backups are immutable or offline to prevent ransomware from encrypting them.
    • Endpoint Detection and Response (EDR) / Antivirus (AV): Deploy and maintain reputable EDR or AV solutions on all endpoints. Ensure they are always updated with the latest threat definitions.
    • Software Updates & Patch Management: Keep operating systems, applications, and firmware fully patched. Ransomware often exploits known vulnerabilities.
    • User Education: Train users to identify phishing attempts, suspicious downloads, and the dangers of pirated software. Emphasize caution when downloading files from unofficial sources.
    • Strong Passwords & Multi-Factor Authentication (MFA): Use strong, unique passwords for all accounts and enable MFA wherever possible, especially for remote access services (RDP, VPN) and cloud accounts.
    • Disable/Restrict RDP: If RDP is necessary, secure it with strong passwords, MFA, network-level authentication (NLA), and restrict access to trusted IPs only. Change default RDP ports.
    • Application Whitelisting: Implement application whitelisting to prevent unauthorized executables (like ransomware) from running on your systems.

2. Removal

  • Infection Cleanup:
    1. Isolate the Infected System: Immediately disconnect the affected computer from all networks (wired and Wi-Fi) to prevent further spread.
    2. Identify and Terminate Malicious Processes: Use Task Manager (Windows) or process explorer tools to identify suspicious processes. Often, ransomware runs under generic names or as services.
    3. Boot into Safe Mode: Restart the computer in Safe Mode (with Networking, if necessary for tool downloads). This can prevent the ransomware from fully executing or interfering with removal tools.
    4. Run Full System Scans: Perform a comprehensive scan using a reputable and updated anti-malware solution (e.g., Malwarebytes, ESET, Bitdefender, Windows Defender Offline). Remove all detected threats.
    5. Clean Temporary Files & Registry: Use disk cleanup tools and consider scanning the registry for suspicious entries that might indicate persistence mechanisms.
    6. Check for Persistence: Examine common persistence locations (e.g., Startup folders, Run keys in Registry, Scheduled Tasks) for any entries related to the ransomware.
    7. Professional Help: For complex or widespread infections, consider engaging a professional cybersecurity incident response team.

3. File Decryption & Recovery

  • Recovery Feasibility: The feasibility of decrypting files encrypted by Djvu/STOP variants like *id62133703* without paying the ransom is highly dependent on the type of encryption key used:
    • Online Keys: Most Djvu/STOP variants, including recent ones, use unique “online” encryption keys generated for each victim and transmitted to the attacker’s command-and-control (C2) servers. If an online key was used, decryption without paying is generally not possible unless the master decryption keys are somehow leaked or a significant cryptographic flaw is discovered in the ransomware’s implementation.
    • Offline Keys: In rare cases, if the victim’s computer cannot connect to the attacker’s C2 server during the encryption process, the ransomware might use a static “offline” key. These offline keys are often reused across multiple victims. If your infection used an offline key, decryption might be possible.
    • NoMoreRansom Project: The Emsisoft decryptor for STOP/Djvu ransomware, available via the NoMoreRansom Project, is the primary tool for recovery. However, it only works for offline keys or if a specific online key has been recovered by security researchers.
    • ID-Ransomware: Always upload a ransom note and an encrypted file to ID-Ransomware.org. This service can identify the specific variant and advise if a decryptor is available for your particular key type (online vs. offline).
  • Essential Tools/Patches:
    • Emsisoft Decryptor for STOP/Djvu: The most recommended tool for attempting decryption (available on NoMoreRansom.org).
    • ID-Ransomware: For identifying the specific variant and checking for decryptor availability.
    • Reputable Anti-malware Software: For removing the ransomware executable.
    • System Restore/Shadow Copies: While Djvu/STOP often attempts to delete Volume Shadow Copies (vssadmin delete shadows /all /quiet), sometimes it fails, or older shadow copies might exist. Check if previous versions of files are available via Windows’ “Restore previous versions” feature.
    • Data Recovery Software: In some cases, if the ransomware deleted original files after encryption (instead of encrypting in place), data recovery tools might be able to recover fragmented or deleted versions of original files, though success is not guaranteed.

4. Other Critical Information

  • Additional Precautions:
    • Information Stealers: A significant characteristic of Djvu/STOP ransomware is that it frequently installs additional malware, particularly information-stealing Trojans (e.g., Vidar Stealer, RedLine Stealer, Azorult), alongside the ransomware itself. These stealers attempt to exfiltrate passwords, cryptocurrency wallet details, browser histories, and other sensitive data before the encryption process begins. A thorough post-infection cleanup must include scanning for and removing these secondary infections.
    • Hosts File Modification: Djvu/STOP often modifies the Windows Hosts file (C:\Windows\System32\drivers\etc\hosts) to block access to security-related websites (e.g., antivirus vendor sites, ransomware information sites). Victims should check and restore their Hosts file to default settings after removal.
    • Fake Decryptors: Be extremely wary of third-party websites offering “free decryptors” for Djvu/STOP ransomware. Many of these are fake and may contain further malware or simply be scams. Always refer to official sources like NoMoreRansom.org.
  • Broader Impact:
    • Volume and Persistence: The Djvu/STOP family is one of the most prolific ransomware threats, constantly evolving with new variants. Its high volume of attacks, particularly targeting individuals and small businesses, makes it a pervasive and costly problem globally.
    • Data Loss Risk: Due to the prevalence of online keys, the Djvu/STOP family often leads to permanent data loss for victims who do not have adequate backups and are unwilling or unable to pay the ransom.
    • Cyber Extortion and Theft: Beyond just file encryption, the inclusion of information stealers elevates the threat to include potential financial fraud and identity theft, making the impact even more severe than typical ransomware.

Combating *id62133703* and other Djvu/STOP variants requires a multi-layered approach focusing heavily on prevention through user education and robust backup strategies, alongside swift and thorough remediation steps if an infection occurs.