@*.banks*

[Content by Gemini 2.5]

This document provides a detailed breakdown of the ransomware variant identified by the file extension @*.banks*, offering insights into its technical characteristics and practical recovery strategies. It is crucial for individuals and organizations to understand these aspects to effectively prevent, detect, and respond to an infection.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Encrypted files by this ransomware variant are typically identified by the appending of the .banks extension. For instance, a file named document.docx would be renamed to document.docx.banks.
  • Renaming Convention: The ransomware follows a pattern where the original filename is preserved, and the .banks extension is simply added at the end. In some observed cases, a unique victim ID or a short string may be prepended or inserted before the .banks extension, such as id-[victim_ID].[original_filename].banks or [random_string]_[original_filename].banks. The @ symbol in the @*.banks* identifier often indicates the naming convention for associated ransom notes, which frequently begin with @ (e.g., @READ_ME_NOW.txt, @DECRYPT_FILES.html), placed in directories containing encrypted files.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The @*.banks* ransomware variant appears to be a relatively recent entrant into the threat landscape, with initial detections and reported outbreaks primarily occurring in late 2023 and continuing into early 2024. Its activity indicates an evolving threat, and security researchers are continually monitoring its spread and variations.

3. Primary Attack Vectors

The @*.banks* ransomware leverages several common yet effective propagation mechanisms to infect systems:

  • Phishing Campaigns: Highly sophisticated phishing emails are a primary vector. These emails often contain malicious attachments (e.g., weaponized documents, password-protected archives containing executables) or links to compromised websites that serve as download points for the ransomware payload. They are frequently tailored to appear legitimate, mimicking communications from known entities or services.
  • Remote Desktop Protocol (RDP) Exploits: Systems with weak or exposed RDP configurations are prime targets. Attackers use brute-force attacks or stolen credentials to gain unauthorized access, subsequently deploying the ransomware manually or via automated scripts.
  • Exploitation of Software Vulnerabilities: @*.banks* can exploit known vulnerabilities in public-facing applications or operating system services.
    • SMBv1/EternalBlue: While older, unpatched systems vulnerable to exploits like EternalBlue (MS17-010) are still susceptible to initial compromise and lateral movement.
    • Web Application Vulnerabilities: Exploitation of vulnerabilities in Content Management Systems (CMS), web servers (e.g., Apache, Nginx), or other internet-facing applications can provide an initial foothold.
  • Malicious Downloads & Drive-by Downloads: Users inadvertently download the ransomware through unofficial software distribution sites, cracked software, key generators, or malicious advertisements (malvertising).
  • Supply Chain Compromise: In some instances, the ransomware might be delivered through a compromised legitimate software update or a component within a trusted software ecosystem.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are the most effective defense against @*.banks*:

  • Regular Data Backups (3-2-1 Rule): Implement a robust backup strategy: at least three copies of your data, stored on two different media types, with one copy offsite or offline (air-gapped). Test your backups regularly to ensure recoverability.
  • Strong Authentication: Enforce strong, unique passwords for all accounts and enable Multi-Factor Authentication (MFA) wherever possible, especially for remote access services (RDP, VPN) and critical systems.
  • Patch Management: Keep operating systems, applications, and firmware fully updated with the latest security patches. Prioritize patches for known vulnerabilities, particularly those in public-facing services.
  • Endpoint Detection and Response (EDR) / Antivirus Software: Deploy reputable EDR or next-generation antivirus solutions on all endpoints and servers. Ensure they are configured for real-time protection and regularly updated.
  • Network Segmentation: Segment your network to isolate critical systems and sensitive data. This limits the lateral movement of ransomware if one segment is compromised.
  • Principle of Least Privilege: Grant users and systems only the minimum necessary permissions required to perform their functions.
  • User Awareness Training: Educate employees about phishing, social engineering tactics, and safe internet practices. Conduct simulated phishing exercises.
  • Disable Unnecessary Services: Disable RDP if not strictly needed, or restrict access to it via VPN and strong firewalls. Disable SMBv1 on all systems.

2. Removal

If an infection is detected, follow these steps to remove @*.banks* from the system:

  • Isolate Infected Systems: Immediately disconnect affected computers and servers from the network (physically or by disabling network adapters). This prevents further spread of the ransomware.
  • Identify and Terminate Malicious Processes: Use Task Manager (Windows) or Activity Monitor (macOS) to identify suspicious processes. For more advanced analysis, use tools like Process Explorer or Autoruns from Sysinternals. Terminate any processes associated with the ransomware.
  • Boot into Safe Mode: Restart the infected system in Safe Mode with Networking (if necessary) to prevent the ransomware from fully executing or reinfecting.
  • Scan and Clean: Perform a full system scan using your updated EDR/antivirus software. Ensure the scan is thorough and removes all detected threats. Consider using multiple reputable anti-malware scanners for comprehensive detection.
  • Check for Persistence Mechanisms: Manually inspect common persistence locations such as:
    • Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run, HKLM\Software\Microsoft\Windows\CurrentVersion\Run)
    • Startup folders
    • Scheduled Tasks
    • Services
      Remove any entries associated with the ransomware.
  • Change All Credentials: Assume that credentials on the infected system (and potentially network credentials if the ransomware spread) have been compromised. Change all passwords for affected user accounts, admin accounts, and service accounts.

3. File Decryption & Recovery

  • Recovery Feasibility: For most new ransomware variants like @*.banks*, public decryptors are typically unavailable. The encryption used is strong (often AES-256 or RSA-2048), and without the private decryption key held by the attackers, file recovery through brute-force or cryptographic methods is generally not feasible.
    • Primary Recovery Method: Backups: The most reliable and recommended method for file recovery is to restore data from clean, verified backups that were taken prior to the infection.
    • Shadow Copies (Volume Shadow Copies): While some ransomware variants attempt to delete Shadow Volume Copies (vssadmin delete shadows /all /quiet), it is worth checking if they are intact. If so, they can be used to restore previous versions of files. Use tools like ShadowExplorer to browse and restore.
    • Data Recovery Software: In some rare cases, data recovery software might be able to recover fragments of unencrypted data if the ransomware did not fully overwrite the original files, but this is often unreliable.
  • Essential Tools/Patches:
    • Security Software: Robust EDR platforms, Next-Generation Antivirus (NGAV) solutions, and reputable anti-malware tools (e.g., Malwarebytes, Sophos, CrowdStrike, SentinelOne).
    • Backup Solutions: Reliable backup software and hardware (e.g., Veeam, Acronis, dedicated NAS/SAN with snapshots).
    • Operating System & Application Patches: Ensure all systems are fully patched via Windows Update, Linux package managers, or macOS Software Update.
    • Network Monitoring Tools: Intrusion Detection/Prevention Systems (IDS/IPS) and Security Information and Event Management (SIEM) systems can help detect anomalous network activity indicative of ransomware presence or lateral movement.

4. Other Critical Information

  • Additional Precautions:
    • Behavioral Detection: @*.banks* might exhibit behaviors like attempting to disable security software, deleting shadow copies, or establishing persistence. Monitor logs for these indicators.
    • Targeted Data Types: While encrypting a wide range of files, some ransomware variants have a preference for commonly used document types, financial records, databases, and media files. Ensure these are prioritized in backup strategies.
    • Double Extortion Threat: Like many modern ransomware groups, the operators behind @*.banks* may engage in “double extortion.” This involves not only encrypting data but also exfiltrating sensitive information before encryption, threatening to publish it if the ransom is not paid. This significantly increases the stakes and compliance risks.
  • Broader Impact:
    • Financial Loss: Direct costs from ransom demands (if paid), recovery expenses, and potential fines for data breaches.
    • Operational Disruption: Significant downtime, loss of productivity, and interruption of critical business operations.
    • Reputational Damage: Loss of customer trust, negative public perception, and long-term harm to brand image.
    • Legal and Regulatory Ramifications: Potential violations of data protection regulations (e.g., GDPR, HIPAA, CCPA) if sensitive data is exfiltrated or compromised, leading to substantial fines and legal action.

Combating @*.banks* (and ransomware in general) requires a multi-layered security approach, emphasizing proactive prevention, rapid detection, and a well-rehearsed incident response plan that prioritizes data recovery from trusted backups.