3pand

[Content by Gemini 2.5]

The ransomware variant identified by the .3pand file extension is a permutation of the highly pervasive STOP/Djvu ransomware family. This family is notorious for its wide distribution and the challenges it poses for file recovery.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this ransomware variant is .3pand.
  • Renaming Convention: Upon successful encryption, the ransomware appends its specific extension to the end of the original filename, typically following the pattern:
    [original_filename].[original_extension].3pand
    For example, a file named document.docx would be renamed to document.docx.3pand. Some variants may also include a unique victim ID before the extension, such as document.docx.id[unique_id].3pand, though .3pand is the consistent identifier.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The broader STOP/Djvu ransomware family has been widely active since late 2017/early 2018. The .3pand specific variant is one of the more recent permutations observed in the latter half of 2023 and continuing into 2024, as the ransomware operators constantly change extensions to evade detection and tracking.

3. Primary Attack Vectors

3pand (like other STOP/Djvu variants) primarily relies on deceptive and user-centric propagation mechanisms rather than exploiting network vulnerabilities:

  • Bundled Software & Illegal Downloads: This is the most prevalent method. Users often get infected by downloading cracked software, key generators, pirated games, or fake software installers from untrusted websites. The ransomware is silently bundled within these seemingly legitimate (but illegal) downloads.
  • Malvertising & Phishing Campaigns: Malicious advertisements or links in phishing emails can redirect users to compromised websites that silently download the ransomware, or trick users into downloading malicious attachments disguised as legitimate documents (e.g., invoices, shipping notifications).
  • Fake Software Updates: Websites promoting fake updates for popular software (like Adobe Flash Player, web browsers, or media players) can serve as a conduit for the ransomware.
  • Compromised Websites: Visiting legitimate websites that have been compromised can sometimes lead to drive-by downloads of the ransomware, though this is less common than the bundled software method for Djvu.
  • Remote Desktop Protocol (RDP) Exploits: While not the primary method for Djvu, weakly secured RDP connections can be exploited by attackers to manually deploy the ransomware onto a victim’s network.

Remediation & Recovery Strategies:

1. Prevention

  • Robust Backups: Implement a 3-2-1 backup strategy (3 copies of data, on 2 different media, 1 copy off-site/offline). Ensure backups are regularly tested and isolated from the primary network to prevent encryption.
  • Reliable Antivirus/Endpoint Detection and Response (EDR): Deploy and keep up-to-date reputable antivirus or EDR solutions with real-time protection and behavioral analysis capabilities.
  • Software Updates & Patch Management: Keep operating systems, applications, and all software regularly updated with the latest security patches to close known vulnerabilities.
  • User Education: Train users about the dangers of downloading cracked software, opening suspicious email attachments, clicking dubious links, and the importance of verifying software sources.
  • Strong Passwords & Multi-Factor Authentication (MFA): Use strong, unique passwords for all accounts and enable MFA wherever possible, especially for remote access services like RDP.
  • Principle of Least Privilege: Limit user permissions to only what is necessary for their job functions.
  • Firewall & Network Segmentation: Employ robust firewall rules and segment networks to limit lateral movement in case of an infection.
  • Disable RDP if Unused: If RDP is not essential, disable it. If used, secure it with strong passwords, MFA, and restrict access to trusted IPs only.

2. Removal

  • 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.
  • Identify the Threat: The presence of files with the .3pand extension and a ransom note (typically named _readme.txt on the desktop and in affected folders) confirms the infection.
  • Run a Full System Scan: Boot the system into Safe Mode with Networking (if possible) or use a bootable antivirus rescue disk. Perform a full scan with a reputable antivirus/anti-malware program (e.g., Malwarebytes, Bitdefender, ESET, Norton, Kaspersky). These tools are often effective at identifying and removing the ransomware executable and associated malicious files.
  • Check for Persistence Mechanisms: Manually inspect common persistence locations (e.g., Windows Registry Run keys, Startup folders, Scheduled Tasks) for any entries related to the ransomware and remove them. Be cautious when editing the registry.
  • Delete Ransomware Files: Once identified by security software, ensure all traces of the ransomware executable and related droppers are removed.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • Limited Decryption Success: Decrypting files encrypted by STOP/Djvu variants, including .3pand, is highly challenging. The ransomware uses two types of encryption keys:
      • Online Key: If the victim’s system has an active internet connection during encryption, a unique online key is generated for that specific victim. These keys are stored on the attackers’ servers, making decryption virtually impossible without their cooperation or a leak of their master keys.
      • Offline Key: If the system is offline during encryption, a pre-generated “offline” key is used. This key is the same for all victims encrypted under offline conditions with that specific variant.
    • Emsisoft Decryptor for STOP/Djvu: Emsisoft, in collaboration with security researchers, has developed a free decryptor tool for STOP/Djvu ransomware. This tool can decrypt files if an offline key was used or if a specific online key has been recovered by researchers. However, it’s crucial to understand that for the vast majority of victims encrypted with an online key, this tool will likely not work.
  • Essential Tools/Patches:
    • Emsisoft Decryptor for STOP/Djvu: Download the latest version from Emsisoft’s official website. Follow their instructions carefully. Be prepared that it may not work for your specific case if an online key was used.
    • Data Recovery Software: Tools like ShadowExplorer or Recuva might help recover previous versions of files from Volume Shadow Copies, though Djvu variants often attempt to delete these. The chances are generally low.
    • System Restore Points: If system restore points were enabled before the infection, you might be able to revert your system to an earlier state, but this will not recover encrypted files unless they were also backed up.
    • Professional Data Recovery: In severe cases, specialized data recovery firms might be able to help, but their success with ransomware-encrypted data is also limited, and it can be very costly.

4. Other Critical Information

  • Additional Precautions:
    • Ransom Note Consistency: The presence of the _readme.txt file is a strong indicator of a STOP/Djvu infection. This note usually instructs victims to contact the attackers via email (e.g., [email protected] or [email protected]) for decryption.
    • Persistence Mechanisms: The ransomware often creates scheduled tasks or modifies registry entries to ensure it restarts with the system. It may also try to block access to security-related websites.
    • Information Stealer Component: Many recent STOP/Djvu variants are bundled with information-stealing malware (e.g., Vidar, Azorult, or Predator The Thief). Even if you recover your files, assume that your sensitive information (passwords, cryptocurrency wallets, browser data) might have been compromised. Change all critical passwords immediately from an uninfected device.
  • Broader Impact:
    • Significant Data Loss: For the majority of victims, irreversible data loss is the most common outcome, especially without robust backups.
    • Operational Disruption: Organizations face severe operational downtime, impacting productivity and revenue.
    • Financial Costs: Recovery efforts can be expensive, involving IT specialists, data recovery services, and potential ransom payments (which are not recommended as they do not guarantee decryption and fund criminal activities).
    • Identity Theft Risk: Due to the info-stealer component, victims face an elevated risk of identity theft, financial fraud, and account compromise.
    • Reputational Damage: Businesses can suffer reputational harm due to a data breach or system downtime.

Recommendation: The most effective defense against .3pand and similar ransomware variants remains robust, isolated backups and a multi-layered cybersecurity strategy focusing on prevention and rapid incident response. Paying the ransom is strongly discouraged.