*[email protected]*.wallet

[Content by Gemini 2.5]

The ransomware variant identified by the file extension *[email protected]*.wallet is a member of the prolific and constantly evolving STOP/Djvu ransomware family. This family is notorious for its wide reach and the consistent challenges it poses for decryption. The email address [email protected] is the specific contact mechanism used by this particular iteration.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The exact file extension used by this variant is typically .[random_string][email protected]. The [random_string] component is usually a short, random set of characters (e.g., .[original_extension][email protected]).
  • Renaming Convention: When a file is encrypted, its name is modified to append this unique extension.
    • Example: A file named document.docx would be renamed to [email protected].
    • Encrypted Data: The file’s content is rendered unusable due to strong encryption.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Variants of the STOP/Djvu ransomware family have been active since late 2018/early 2019. Specific iterations like the *[email protected]*.wallet variant continuously emerge as the threat actors update their code. This particular variant likely appeared in late 2023 or early 2024, following the established pattern of new STOP/Djvu strains appearing regularly with updated extensions and contact emails. New variants are released almost daily, making precise timeline tracking challenging for individual strains.

3. Primary Attack Vectors

*[email protected]*.wallet (like other STOP/Djvu variants) primarily relies on stealthy, user-initiated execution:

  • Software Cracks/Pirated Software: This is the most prevalent vector. Users download “cracked” versions of popular software, key generators, or activators from torrent sites and untrusted file-sharing platforms. The ransomware is bundled within these seemingly legitimate installers.
  • Phishing Campaigns: While less common for STOP/Djvu than for some enterprise-targeting ransomware, basic phishing emails with malicious attachments (e.g., weaponized documents, zip files containing executables) or links to compromised websites can be used.
  • Malvertising/Drive-by Downloads: Redirects from malicious advertisements on legitimate or compromised websites can lead to silent downloads and execution of the ransomware.
  • Fake Software Updates: Pop-ups masquerading as critical browser or system updates that, when clicked, download and execute the malware.
  • Unpatched Software Vulnerabilities: Less frequently, but still a possibility, the ransomware could exploit known vulnerabilities in software or operating systems, though this is not a primary modus operandi for this specific family compared to more sophisticated ransomware operations.
  • Remote Desktop Protocol (RDP) Exploits: While not a primary propagation method for initial infection by STOP/Djvu, if an RDP port is exposed and poorly secured, it could be manually exploited by an attacker to deploy this ransomware.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are the most effective defense against *[email protected]*.wallet and similar threats:

  • Robust Backup Strategy: Implement 3-2-1 backup rule (3 copies, 2 different media types, 1 offsite/offline). Ensure backups are regularly tested, immutable, and isolated from the network to prevent encryption.
  • Software Updates & Patch Management: Keep operating systems, applications (especially web browsers, email clients, and productivity suites), and security software up to date with the latest patches.
  • Antivirus/Endpoint Detection and Response (EDR): Deploy and maintain a reputable antivirus solution or, for organizations, an EDR solution on all endpoints. Configure it for real-time protection and regular scans.
  • User Education & Awareness Training: Train users to identify phishing attempts, suspicious links, and the dangers of downloading pirated software. Emphasize the risks of disabling security software.
  • Strong Password Policies & Multi-Factor Authentication (MFA): Use strong, unique passwords for all accounts. Enable MFA wherever possible, especially for critical services and remote access.
  • Network Segmentation: Divide networks into smaller, isolated segments to limit lateral movement of ransomware if an infection occurs.
  • Disable Unnecessary Services/Protocols: Turn off RDP if not needed, or secure it with strong passwords, MFA, and network-level restrictions if necessary. Disable SMBv1.
  • Application Whitelisting: Restrict the execution of unauthorized applications. This is highly effective against unknown malware.
  • Firewall Rules: Implement robust firewall rules to block suspicious inbound/outbound connections.
  • Block Common Malicious IP/Domains: Utilize threat intelligence to block known malicious IP addresses and domains at the perimeter.

2. Removal

Effective removal requires careful, step-by-step execution:

  1. Isolate the Infected System: Immediately disconnect the infected computer from the network (unplug Ethernet cable, disable Wi-Fi). This prevents further spread to other devices.
  2. Identify the Threat: Do not immediately try to delete files. The ransomware often drops a ransom note (typically _readme.txt) on the desktop and in affected folders. This note contains the attacker’s demands and contact information ([email protected]). Analyzing the file extension and the ransom note helps confirm the specific variant.
  3. Scan and Remove: Boot the infected system into Safe Mode (with Networking, if necessary, to download tools). Use a reputable and updated antivirus/anti-malware scanner to perform a full system scan. Tools like Malwarebytes, Emsisoft Anti-Malware, or the removal tool from your primary AV vendor are often effective.
    • Note: While AV can remove the executable, it won’t decrypt the files.
  4. Check for Persistence: Examine common persistence locations (e.g., Startup folders, Registry Run keys, Scheduled Tasks, WMI event subscriptions) for any entries related to the ransomware. Remove them manually or using specialized tools if identified.
  5. Change All Passwords: After confirming the system is clean, change all passwords used on or accessible from the infected machine (e.g., network shares, cloud services, email accounts).
  6. Reinstall Operating System (Recommended for Servers/Critical Systems): For critical systems or if there’s any doubt about complete removal, a clean reinstallation of the operating system is the most secure approach. This ensures no remnants of the malware or backdoors remain.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • Online Key Variants: For *[email protected]*.wallet, decryption is generally not possible without paying the ransom or obtaining the private key from the attackers. This variant uses strong, modern encryption (AES and RSA) and typically generates a unique encryption key for each victim (an “online key”).
    • Offline Key Variants: In rare cases, if the ransomware fails to connect to its command-and-control server (e.g., due to internet connectivity issues at the time of infection), it might use a default “offline key.” Decryptors like the one provided by Emsisoft for STOP/Djvu may be able to decrypt files encrypted with an offline key, provided the specific offline key used by this variant has been recovered by security researchers. However, the [email protected] variant is highly likely to use an online key.
    • Shadow Volume Copies: STOP/Djvu ransomware variants, including this one, actively attempt to delete Shadow Volume Copies using vssadmin.exe. Therefore, relying on these for recovery is usually futile unless the deletion attempt failed for some reason.
    • Data Recovery Software: In limited scenarios, data recovery software might recover older, unencrypted versions of files if they weren’t completely overwritten, but this is an extremely low-probability scenario for ransomware-encrypted files.
  • Methods/Tools:
    • Emsisoft Decryptor for STOP/Djvu: This is the only publicly available decryptor for STOP/Djvu. You can download it from their official website. Important: It requires sample encrypted files and the ransom note to check if an offline key matches or if an online key has been recovered for your specific ID. Do not expect success if an online key was used.
    • Professional Data Recovery Services: Some specialized companies might offer recovery services, but they are often very expensive and cannot guarantee success. Many simply pay the ransom on your behalf.
  • Essential Tools/Patches:
    • Emsisoft Decryptor for STOP/Djvu: For attempting file recovery.
    • Reputable Antivirus/Anti-Malware: (e.g., Malwarebytes, ESET, Sophos, Microsoft Defender) for removal.
    • Operating System Updates: Ensure Windows/macOS is fully patched.
    • Browser Updates: Keep web browsers updated.
    • Security Tools: VPNs for secure remote access, MFA apps.

4. Other Critical Information

  • Unique Characteristics:
    • Information Stealer Integration: Many recent STOP/Djvu variants are bundled with information-stealing malware (e.g., Vidar, RedLine, Azorult). This means that even if you recover your files, your sensitive data (browser passwords, cryptocurrency wallet seeds, session tokens, personal files) may have already been exfiltrated.
    • False “Update” Process: The ransomware often masquerades as a legitimate software update process during infection to lull users into a false sense of security.
    • Offline Key Potential (Limited): The slim chance of an “offline key” decryption for certain victims is a distinguishing feature, but it’s increasingly rare with newer variants.
  • Broader Impact:
    • High Volume Infections: STOP/Djvu is one of the most widespread consumer-targeting ransomware families, leading to a vast number of individual and small business infections globally.
    • Financial Burden: The ransom demand for individual users is typically between $490 and $980 (often with a “discount” if paid quickly), which can be a significant burden for individuals.
    • Data Theft Risk: The bundling with info-stealers means victims face not only data loss but also potential identity theft, financial fraud, and account compromise, complicating post-incident recovery significantly.
    • Resource Drain: The sheer volume of infections places a considerable burden on cybersecurity companies, help desks, and individuals seeking assistance.