0.locked

[Content by Gemini 2.5]

The ransomware variant identified by the file extension .0.locked is primarily associated with the GlobeImposter ransomware family, specifically one of its numerous variants. GlobeImposter is known for its constantly evolving nature, often adopting new file extensions and slightly altered ransom note formats.

Here’s a detailed breakdown of this specific variant:

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this variant is .0.locked.
  • Renaming Convention: When a file is encrypted by this GlobeImposter variant, its original name is typically appended with the unique victim ID, the attacker’s email address (or another identifier), and finally the .0.locked extension.
    • Example: A file named document.docx might be renamed to document.docx.[ID-string].[email].0.locked or document.docx.[RandomString].0.locked. The specific pattern can vary slightly between sub-variants.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Variants of the GlobeImposter ransomware family, including those using the .0.locked extension, were widely detected and began to spread significantly around late 2017 and throughout 2018, with new iterations appearing periodically thereafter. GlobeImposter has consistently been a prevalent threat, especially targeting businesses.

3. Primary Attack Vectors

GlobeImposter, including the .0.locked variant, primarily utilizes the following propagation mechanisms:

  • Remote Desktop Protocol (RDP) Exploits: A very common method. Attackers gain access to systems via exposed and weakly secured RDP ports, often by brute-forcing weak passwords or using stolen credentials. Once inside, they manually deploy the ransomware.
  • Phishing Campaigns: Malicious emails containing infected attachments (e.g., seemingly legitimate documents with embedded macros) or links to malicious websites that deliver the ransomware payload.
  • Exploit Kits (EKs): While less common in recent years compared to their peak, some GlobeImposter variants have been distributed via exploit kits that leverage vulnerabilities in outdated software (e.g., Flash, Java, web browsers) to silently install the malware when a user visits a compromised website.
  • Malvertising: Distribution through malicious advertisements on legitimate websites, which redirect users to exploit kits or directly download the ransomware.
  • Software Vulnerabilities: Exploiting known vulnerabilities in commonly used software or operating systems, though RDP remains a more dominant vector for GlobeImposter’s targeted attacks.

Remediation & Recovery Strategies:

1. Prevention

  • Robust Backup Strategy: Implement regular, automated backups of all critical data. Follow the 3-2-1 rule: 3 copies of your data, on 2 different media, with 1 copy off-site or air-gapped. Test your backups regularly.
  • Patch Management: Keep operating systems, software, and applications (especially web browsers, email clients, and common plugins like Adobe Reader/Flash) fully updated with the latest security patches.
  • Strong RDP Security:
    • Disable RDP if not absolutely necessary.
    • If RDP is required, place it behind a VPN, use multi-factor authentication (MFA), and use strong, complex passwords.
    • Limit RDP access to specific trusted IP addresses.
    • Monitor RDP logs for unusual activity.
  • Network Segmentation: Divide your network into segments to limit the lateral movement of ransomware if an infection occurs in one area.
  • Email Security & User Training: Implement email filtering solutions to block malicious attachments and links. Educate employees about phishing, suspicious emails, and the dangers of clicking unknown links or opening attachments from untrusted sources.
  • Endpoint Detection and Response (EDR) / Next-Gen Antivirus: Deploy advanced security solutions that use behavioral analysis to detect and block ransomware activities, even for new variants.
  • Principle of Least Privilege: Grant users and systems only the minimum necessary permissions to perform their tasks.

2. Removal

  • Immediate Isolation: Disconnect the infected system(s) from the network immediately to prevent further spread (e.g., unplug network cables, disable Wi-Fi).
  • Identify & Document: Note down the ransomware variant (GlobeImposter, .0.locked), the ransom note content, and any renamed files. This information is crucial for analysis and potential decryption.
  • Scan with Reputable Antivirus/Anti-Malware: Boot the infected system into Safe Mode with Networking (if possible) or use a bootable anti-malware rescue disk. Run a full system scan with up-to-date security software (e.g., Malwarebytes, ESET, Kaspersky, Sophos). This will identify and remove the ransomware executable and associated dropper files.
  • Check for Persistence: Look for persistence mechanisms (e.g., registry run keys, scheduled tasks, startup folders) that the ransomware might have established. Remove any suspicious entries.
  • Review System Logs: Check system event logs (security, application) for unusual activity leading up to the infection.

3. File Decryption & Recovery

  • Recovery Feasibility: Yes, in many cases, it is possible to decrypt files encrypted by certain GlobeImposter variants, including some that use the .0.locked extension. This is a significant advantage compared to many other ransomware families.
  • Methods/Tools Available:
    • No More Ransom! Project: The “No More Ransom!” initiative (a collaboration between law enforcement and cybersecurity companies) often hosts free decryptors for various ransomware families. It is the primary place to check for a GlobeImposter decryptor.
    • Emsisoft Decryptor: Emsisoft provides a free decryptor specifically for GlobeImposter ransomware. You will typically need a sample of an encrypted file and the ransom note to assist the tool in identifying the specific GlobeImposter variant and key.
    • Other Security Vendors: Other cybersecurity firms like Avast, Kaspersky, or Trend Micro may also offer tools or guidance.
    • Data Recovery from Backups: The most reliable and recommended method is to restore your data from clean, recent backups. This bypasses the need for decryption and ensures data integrity.
    • Shadow Volume Copies: While many modern ransomware strains attempt to delete Shadow Volume Copies (VSS), it’s always worth checking if they exist on your system and trying to recover previous versions of files. This is less likely to succeed with GlobeImposter, but not impossible if the ransomware failed to execute the deletion command properly.
  • Essential Tools/Patches:
    • GlobeImposter Decryptor (e.g., Emsisoft GlobeImposter Decryptor): Essential for decryption attempts.
    • Up-to-date Antivirus/Anti-malware software: For detection and removal.
    • Data Backup Solutions: Critical for recovery.
    • Patch Management System: To ensure all software is up-to-date.
    • RDP Security Tools: (e.g., VPNs, MFA solutions, IP whitelisting) for prevention.

4. Other Critical Information

  • Additional Precautions:
    • “Imposter” Nature: The name “GlobeImposter” stems from its historical tendency to impersonate other more famous ransomware families (like WannaCry or Petya in some early forms) to confuse victims and researchers. While the .0.locked extension is specific, be aware that GlobeImposter is highly adaptable with its extensions.
    • Automated vs. Manual Deployment: While it can spread via exploit kits, many GlobeImposter infections (especially RDP-based ones) involve attackers manually deploying the ransomware after gaining initial access, making it a more targeted attack against businesses.
    • Ransom Note Consistency: The ransom note often appears as HOW TO RESTORE YOUR FILES.TXT, DECRYPT_INSTRUCTION.HTML, or DECRYPT_INSTRUCTION.url on the desktop or in affected folders. It typically contains instructions to contact an email address (often a ProtonMail or Tutanota address) and sometimes a unique ID.
  • Broader Impact: GlobeImposter, including its .0.locked variant, has caused significant disruption to businesses worldwide due to its reliance on RDP vulnerabilities. Its consistent activity and evolution make it a persistent threat that organizations must actively defend against. The availability of decryptors for some variants offers a glimmer of hope for victims, but prevention and robust backup strategies remain paramount.