*bomani@*

[Content by Gemini 2.5]

The ransomware variant identified by the file extension *bomani@* is a member of the STOP/Djvu ransomware family, one of the most prolific and continuously evolving strains targeting individual users and small businesses globally. While the @ symbol might specifically refer to an email address mentioned in its ransom note or contact details, the core file extension associated with this variant is typically .bomani.

Here’s a detailed breakdown:

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files encrypted by this ransomware variant will append .bomani to their original file names. For example, a file named document.docx would become document.docx.bomani.
    • Note on *bomani@*: While the prompt uses *bomani@*, the actual file extension is .bomani. The @ symbol likely refers to the contact email address (e.g., [email protected]) often found within the ransom note, which is common for Djvu variants to include in their communication instructions.
  • Renaming Convention: The pattern follows the standard Djvu convention: <original_filename>.<original_extension>.<bomani>.
    • Example: image.jpg becomes image.jpg.bomani
    • Example: report.pdf becomes report.pdf.bomani

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The .bomani variant of STOP/Djvu ransomware was first detected and reported around late 2023 to early 2024. The STOP/Djvu family itself has been active since early 2018, with new variants released almost daily.

3. Primary Attack Vectors

The bomani variant, like other Djvu ransomware, primarily relies on social engineering and deceptive tactics rather than complex network exploits. Its main propagation mechanisms include:

  • Cracked Software & Illicit Downloads: This is the most prevalent method. Users download cracked versions of popular software (e.g., Adobe Photoshop, Microsoft Office, video games), key generators (keygens), or software activators from torrent sites and untrusted download portals. The ransomware is bundled within these seemingly legitimate files.
  • Fake Software Updates: Malicious websites or pop-ups may trick users into downloading what appears to be a critical software update (e.g., for Flash Player, web browsers, or codecs), which is actually the ransomware payload.
  • Malvertising & Compromised Websites: Users browsing compromised legitimate websites or interacting with malicious advertisements might be redirected to pages that silently download the ransomware or prompt them to download a “necessary” file.
  • Phishing Campaigns (Less Common for Djvu, but Possible): While less common than for enterprise-focused ransomware, some Djvu variants might be distributed via email attachments disguised as invoices, shipping notifications, or other legitimate documents.
  • Remote Desktop Protocol (RDP) Exploits (Less Common): In some cases, if RDP ports are exposed and weakly secured, attackers could gain access to a system and manually deploy the ransomware. However, this is not a primary or scalable method for Djvu’s widespread distribution.

Remediation & Recovery Strategies:

1. Prevention

Proactive measures are crucial to prevent a bomani infection:

  • Regular Backups: Implement a robust 3-2-1 backup strategy (3 copies, 2 different media types, 1 offsite). Ensure backups are isolated from the network to prevent encryption.
  • Reputable Antivirus/Anti-Malware Software: Install and keep updated a comprehensive security suite with real-time protection and behavioral analysis capabilities.
  • Software and OS Updates: Regularly update your operating system, applications, and web browsers. Patches often fix vulnerabilities that ransomware exploits.
  • Exercise Caution with Downloads:
    • Avoid downloading cracked software, keygens, or pirated content.
    • Only download software from official vendor websites or trusted app stores.
    • Be wary of unsolicited links or attachments in emails.
  • Ad-Blockers: Use reputable ad-blockers to prevent malvertising.
  • Strong Passwords & Multi-Factor Authentication (MFA): Especially for RDP, VPN, and critical accounts.
  • Network Segmentation: For businesses, segmenting your network can limit the spread of ransomware if one segment becomes infected.
  • User Education: Educate users about the risks of phishing, suspicious downloads, and safe browsing habits.

2. Removal

If infected, follow these steps to remove the bomani ransomware:

  1. Isolate the Infected System: Immediately disconnect the infected computer from the network (unplug Ethernet cable, disable Wi-Fi). This prevents the ransomware from spreading to other devices.
  2. Identify and Terminate Malicious Processes:
    • Open Task Manager (Ctrl+Shift+Esc). Look for suspicious processes consuming high CPU or memory.
    • Use a tool like Process Explorer from Sysinternals for more detailed insights.
  3. Boot into Safe Mode: Restart the computer and boot into Safe Mode with Networking. This loads only essential services, preventing the ransomware from running.
  4. Perform Full System Scan:
    • Run a full scan using your updated antivirus/anti-malware software (e.g., Windows Defender, Malwarebytes, SpyHunter).
    • It’s recommended to use multiple scanners as one might catch what another misses.
  5. Remove Persistence Mechanisms:
    • Check Startup folders (type shell:startup in Run dialog).
    • Check Registry Run keys (HKEYCURRENTUSER\Software\Microsoft\Windows\CurrentVersion\Run and HKEYLOCALMACHINE\Software\Microsoft\Windows\CurrentVersion\Run).
    • Check Task Scheduler for suspicious scheduled tasks.
  6. Delete Ransomware Files: Once identified by security software, ensure all associated ransomware files are quarantined or deleted. Common locations include %APPDATA%, %TEMP%, and %LOCALAPPDATA%.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • Offline Keys (Feasible): Many Djvu variants, including bomani, use “offline keys” when the ransomware cannot establish a connection to its command-and-control (C2) server during encryption. If your files were encrypted with an offline key, decryption is often possible using free tools.
    • Online Keys (Not Feasible without Key): If the ransomware successfully connected to its C2 server, it generated a unique “online key” for your specific infection. Decryption using public tools is not possible for files encrypted with an online key, as the key is unique to you and unknown to researchers. Paying the ransom is strongly discouraged as there’s no guarantee of decryption, and it fuels future attacks.
  • Essential Tools/Patches:
    • Emsisoft Decryptor for STOP/Djvu: This is the primary tool for decrypting files encrypted by STOP/Djvu variants. It can be downloaded from the No More Ransom! website (https://www.nomoreransom.org/). You will need to submit a few encrypted files and the ransom note to the site’s Crypto Sheriff tool, which will identify the variant and link to the appropriate decryptor.
    • Shadow Volume Copies: Ransomware often deletes these, but in rare cases, they might be intact. You can attempt to recover previous versions of files using Windows’ built-in “Previous Versions” feature.
    • Data Recovery Software: For highly fragmented or partially overwritten files, specialized data recovery software might retrieve some data, but it’s not a reliable decryption method.

4. Other Critical Information

  • Additional Precautions & Characteristics:
    • Ransom Note: The bomani variant typically drops a ransom note named _readme.txt in every folder containing encrypted files, and on the desktop. This note provides instructions for payment and contact information.
    • Host File Modification: Djvu variants often modify the Windows hosts file to block access to security-related websites (e.g., antivirus vendors, cybersecurity blogs) to prevent victims from seeking help or downloading security tools. You should check and reset your hosts file.
    • Information Stealer Payload: A significant and dangerous characteristic of Djvu ransomware is its frequent bundling with an info-stealer malware (e.g., Vidar Stealer, RedLine Stealer). This secondary payload attempts to steal sensitive data such as browser credentials, cryptocurrency wallets, documents, and system information before the encryption process even begins. This means even if you recover your files, your personal data might already be compromised.
    • Self-Deletion of Shadow Copies: The ransomware attempts to delete Shadow Volume Copies using commands like vssadmin.exe delete shadows /all /quiet to prevent easy recovery.
  • Broader Impact: The STOP/Djvu family, including bomani, represents a significant threat to individual users and small businesses due to its widespread distribution via popular, often illicit, channels. Its continuous evolution and the inclusion of information-stealing capabilities make it particularly insidious, posing both data loss and identity theft risks. The high volume of variants makes it challenging for security researchers to develop universal decryptors immediately for every new online key variant.