*[email protected]*.wallet

[Content by Gemini 2.5]

The ransomware variant identified by the file extension *[email protected]*.wallet is a strong indicator of an infection by a variant of the STOP/Djvu ransomware family. This family is one of the most prolific and widespread ransomware types, constantly evolving with new variants appearing regularly. The email address ([email protected]) embedded in the file extension serves as a unique identifier for this specific variant within the broader STOP/Djvu lineage.

Here’s a detailed breakdown and recovery guide:

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this variant is .[[email protected]].wallet. This means that after encryption, files will have this suffix appended to their original names.
  • Renaming Convention: The typical renaming pattern follows:
    [original_filename].[[email protected]].wallet
    For example, document.docx might become document.docx.[[email protected]].wallet.
    In some STOP/Djvu variants, an ID string might be included, like [original_filename].id[ID_STRING].[[email protected]].wallet, but the core identifier remains the email and .wallet extension.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: While a precise “start date” for the [email protected] variant specifically can be difficult to pinpoint without direct threat intelligence monitoring, the broader STOP/Djvu ransomware family has been active since at least late 2017/early 2018. New variants like this one emerge almost daily or weekly. The [email protected] variant would have likely appeared within the last several months as a newer iteration of this persistent threat. Its widespread distribution aligns with the continuous, high-volume nature of STOP/Djvu infections.

3. Primary Attack Vectors

STOP/Djvu ransomware, including the [email protected] variant, primarily propagates through deceptive methods targeting individual users rather than exploiting network-level vulnerabilities like EternalBlue (which are more common for worms or enterprise-grade ransomware).

  • Propagation Mechanisms:
    • Software Cracks & Pirated Software: This is the most prevalent vector. Users seeking cracked software, key generators, or pirated games from unofficial websites, torrents, or download sites often unknowingly download executables bundled with the ransomware. The ransomware masquerades as the desired software or an essential component.
    • Malicious Downloads & File-Sharing Sites: Similarly, free software, media files, or documents downloaded from untrustworthy file-sharing platforms are common carriers.
    • Phishing Campaigns (Malspam): Though less frequent for Djvu compared to other ransomware families, email-based phishing can be used. This involves malicious attachments (e.g., infected Word/Excel documents with macros, or ZIP archives containing executables) or links to compromised websites that host the malware.
    • Malvertising (Malicious Advertisements): Clicking on deceptive advertisements on legitimate or compromised websites can redirect users to malicious landing pages that initiate a drive-by download or trick the user into downloading the ransomware.
    • Fake Updates: Prompts for fake software updates (e.g., Flash Player, Java, browser updates) often lead to the download of the ransomware payload.
    • Remote Desktop Protocol (RDP) Exploits: While less common for Djvu’s typical distribution model, compromised RDP credentials are a general ransomware attack vector. If an attacker gains access via RDP, they can manually deploy the ransomware.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to avoid infection by *[email protected]*.wallet and similar ransomware variants:

  • Regular Data Backups: Implement a robust backup strategy following the 3-2-1 rule (3 copies of data, 2 different media types, 1 offsite/cloud). Ensure backups are isolated from the network to prevent encryption.
  • Software Updates & Patch Management: Keep your operating system (Windows), web browsers, antivirus software, and all applications updated. Vulnerabilities in outdated software are frequently exploited.
  • Strong Antivirus/Anti-Malware: Use a reputable, up-to-date antivirus suite with real-time protection and behavioral analysis capabilities.
  • Email Security Awareness: Be extremely cautious with unsolicited emails. Never open suspicious attachments or click on links from unknown senders. Verify the sender and content before interacting.
  • Avoid Pirated Software & Illegal Downloads: This is paramount for preventing Djvu infections. Stick to official sources for software and media.
  • Disable RDP if Not Needed: If RDP is necessary, secure it with strong, unique passwords, multi-factor authentication (MFA), and restrict access to specific IP addresses or VPNs.
  • Firewall Configuration: Configure your firewall to block suspicious incoming and outgoing connections.
  • Ad Blockers: Use reputable ad blockers to mitigate the risk of malvertising.
  • User Account Control (UAC): Do not disable UAC; it can provide a layer of protection against unauthorized changes.
  • System Restore Points: While often deleted by ransomware, having System Restore Points enabled can sometimes aid in recovery of system files (though not encrypted user data).

2. Removal

If infected, follow these steps to remove *[email protected]*.wallet:

  1. Isolate the Infected System: Immediately disconnect the infected computer from the internet and any local networks (unplug Ethernet cable, disable Wi-Fi). This prevents further spread and communication with the attacker’s command-and-control server.
  2. Identify the Ransom Note: Look for a text file, typically named _readme.txt, on the desktop or in encrypted folders. This file contains the ransom demand and instructions. Do not pay the ransom.
  3. Boot into Safe Mode: Restart your computer and boot into Safe Mode (with Networking, if you need to download tools). This limits the ransomware’s ability to run.
  4. Scan with Reputable Anti-Malware Tools:
    • Download and run a full scan with your primary antivirus software.
    • Supplement with reputable secondary scanners like Malwarebytes, Emsisoft Anti-Malware, or HitmanPro. Ensure these tools are updated to their latest definitions.
    • The ransomware often tries to disable security software; you may need to run these tools from Safe Mode or use a bootable anti-malware rescue disk (e.g., ESET SysRescue Live, Kaspersky Rescue Disk).
  5. Remove Persistent Elements:
    • Check Task Manager for suspicious processes and terminate them.
    • Examine startup folders (type shell:startup in Run dialog) and Registry Run keys (regedit, navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run and HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run) for entries related to the ransomware. Remove any suspicious entries.
    • The ransomware often modifies the hosts file (C:\Windows\System32\drivers\etc\hosts) to block access to security websites. Edit this file and remove any suspicious entries.
  6. Delete Shadow Copies: While ransomware usually deletes them, attempt to recover using vssadmin delete shadows /all /quiet (though this might already be done). This is more for general cleanup.
  7. Change All Passwords: After confirming the system is clean, change all passwords for online accounts accessed from the infected system, especially email, banking, and critical services. Consider using a different, clean device for this.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • Limited Decryption: For most modern STOP/Djvu variants, including [email protected], full decryption is highly unlikely without the attacker’s private key if an “online” key was used (which is typical).
    • Emsisoft Decryptor: Emsisoft, in collaboration with security researchers, provides a free decryptor for STOP/Djvu ransomware. However, this decryptor primarily works for older variants or if your system was infected with an “offline” key. An offline key is used when the ransomware cannot establish communication with its command-and-control server. If the decryptor indicates an “online ID,” decryption is not possible with current public tools. You can submit encrypted files to Emsisoft’s decryption tool for analysis, but prepare for the likelihood of no successful decryption.
    • No Guarantee: Even with tools, success depends on the specific variant and whether it used an online or offline key. New variants constantly emerge, rendering older decryptors ineffective.
  • Essential Tools/Patches:
    • Emsisoft STOP/Djvu Decryptor: This is the primary tool to attempt decryption. Download it only from Emsisoft’s official website.
    • Reputable Antivirus/Anti-Malware Software: Tools like Malwarebytes, ESET, Bitdefender, Kaspersky are crucial for removal.
    • Windows Updates: Ensure your Windows OS is fully patched to prevent exploitation of known vulnerabilities.
    • Data Recovery Software (as a last resort): Tools like Recuva or PhotoRec might be able to recover fragmented data from shadow copies if they weren’t fully deleted, or from unallocated space, but success is usually low after ransomware.
    • Backup & Restore Solutions: This is the most effective recovery method. Restore data from clean, isolated backups.

4. Other Critical Information

  • Unique Characteristics:
    • Embedded Email in Extension: The direct inclusion of an email address ([email protected]) within the encrypted file extension is a hallmark of STOP/Djvu. This email is intended for victims to contact the attackers but is also a unique identifier for the variant.
    • _readme.txt Ransom Note: The consistent use of _readme.txt as the ransom note filename across nearly all STOP/Djvu variants.
    • Hosts File Modification: Many Djvu variants modify the Windows hosts file to block access to security-related websites (e.g., those providing decryption tools or antivirus updates), hindering victim’s recovery efforts.
    • Offline vs. Online Keys: The reliance on online keys when C2 communication is successful, which makes decryption practically impossible, distinguishes it from older ransomware that might have used deterministic or limited key sets.
    • Persistence Mechanisms: Often establishes persistence via registry run keys or scheduled tasks to re-encrypt files if not fully removed.
  • Broader Impact:
    • Significant Data Loss: For individuals and organizations without proper backups, [email protected].wallet (like other Djvu variants) leads to irreversible data loss.
    • Financial Costs: Paying the ransom is strongly discouraged as it funds criminal activities and does not guarantee decryption. Recovery efforts (IT support, new hardware, lost productivity) can be costly.
    • Operational Disruption: For businesses, infection can lead to significant downtime, impacting operations, customer service, and revenue.
    • Psychological Stress: Victims often experience considerable stress and frustration due to the loss of irreplaceable personal files or critical business data.
    • Contribution to Cybercrime Economy: Each successful infection and ransom payment fuels the ransomware ecosystem, encouraging attackers to continue and refine their methods.

In summary, *[email protected]*.wallet is a persistent and disruptive ransomware variant from the STOP/Djvu family. The best defense is a proactive, multi-layered prevention strategy, as decryption after infection is often not feasible.