FOX Ransomware

FOX ransomware is a variant within the notorious Dharma family, designed to encrypt user files and demand a ransom for decryption. Detected during an inspection of malware samples submitted to VirusTotal, FOX has demonstrated typical characteristics of ransomware attacks—encrypting local and network files, appending a specific extension, and leaving a ransom note both as a pop-up message and in an “info.txt” file.

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Threat Summary

Below is a table summarizing the key details of FOX ransomware:

Detail	Description
Threat Type	Ransomware, Crypto Virus, Files Locker
Encrypted File Extension	.SCRT (e.g., “1.jpg” is renamed to “1.jpg.id-9ECFA84E.[secretuser@tuta.io].SCRT”)
Ransom Note File Name	info.txt and a pop-up message displayed on the victim’s desktop
Associated Email Addresses	secretuser@tuta.io and secretuser@mailum.com
Detection Names	Avast (Win32:RansomX-gen [Ransom]), Combo Cleaner (Trojan.Ransom.Crysis.E), ESET-NOD32 (A Variant Of Win32/Filecoder.Crysis.P), Kaspersky (Trojan-Ransom.Win32.Crusis.to), Microsoft (Ransom:Win32/Wadhrama!pz)
Symptoms of Infection	Files become inaccessible, renamed with additional identifiers and the .SCRT extension; a ransom note appears; encrypted files cannot be opened normally
Damage	Encryption of all accessible files with no straightforward recovery option; potential for additional malware (e.g., password stealers) to be installed alongside ransomware
Distribution Methods	Exploitation of vulnerable RDP services, deceptive email attachments (including malicious macros), pirated software, torrent websites, malicious ads, and technical support scams
Danger Level	High—due to extensive file encryption, potential secondary malware infections, and the lack of a free decryptor

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Detailed Analysis of FOX Ransomware

How FOX Operates

FOX ransomware works by encrypting files on both local and network drives, ensuring that once a system is infected, all accessible data becomes locked. The malware appends a unique identifier and a predetermined email address to the file names along with a new extension. For example:

• Original file: 1.jpg
• Encrypted file: 1.jpg.id-9ECFA84E.[secretuser@tuta.io].SCRT

This renaming pattern indicates not only the encryption but also ties the victim’s files to a unique ID which the attackers can use to manage ransom communications.

Ransom Note Details

Upon encryption, FOX displays a ransom note through both a pop-up message and an "info.txt" file. The messages contain instructions for contacting the attackers and include the following texts:

Pop-Up Message:

FOX
YOUR FILES ARE ENCRYPTED
Don't worry, you can return all your files!
If you want to restore them, write to the mail: secretuser@tuta.io YOUR ID -
If you have not answered by mail within 24 hours, write to us by another mail:secretuser@mailum.com
ATTENTION
FOX does not recommend contacting agent to help decode the data

Text File (info.txt):

You want to return?
write email secretuser@tuta.io or secretuser@mailum.com

These messages are crafted to induce panic and urgency, pressuring victims into contacting the attackers through the specified email addresses.

Technical Characteristics

FOX ransomware shares several common traits with other members of the Dharma family:

• Encryption Mechanism: It encrypts files using a robust algorithm, making it nearly impossible to recover files without the decryption key.
• Persistence: FOX ensures it remains active on the system by copying itself to the %LOCALAPPDATA% directory and adding entries to the Windows Registry’s Run keys.
• Disabling Defenses: It attempts to disable system firewalls and deletes Volume Shadow Copies to thwart attempts at system recovery.
• Location Awareness: FOX gathers location data and can exclude specific, predefined locations from its encryption process, adding a layer of complexity to its operation.

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Removing FOX Ransomware

SpyHunter is a reputable malware removal tool known for its effectiveness against a wide range of threats, including ransomware. The following guide outlines the steps to remove FOX ransomware using SpyHunter:

Step 1: Download and Install SpyHunter

1. Obtain the Software:
   Download the latest version of the software. Ensure you are downloading from the legitimate source to avoid counterfeit or infected versions.
2. Installation:
   Run the installer and follow the on-screen instructions. Accept the license agreement and complete the installation process.
3. Initial Setup:
   After installation, update SpyHunter to ensure you have the most recent malware definitions and removal capabilities.

Step 2: Run a Full System Scan

1. Launch SpyHunter:
   Open the SpyHunter application.
2. Initiate a Full Scan:
   Select the option for a full system scan. This process might take some time, depending on the number of files and system performance.
3. Review Scan Results:
   Once the scan is complete, SpyHunter will display a list of detected threats. Look for any entries related to FOX ransomware or any other suspicious files that might be part of the infection.

Step 3: Quarantine or Remove Detected Threats

1. Select Detected Threats:
   From the scan results, select all items flagged as malicious, especially those linked to FOX ransomware.
2. Quarantine/Removal:
   Choose the option to quarantine or delete the malicious files. Quarantining isolates the files, preventing further harm while allowing you to restore them if necessary. However, for ransomware, removal is generally recommended since the files are encrypted and likely unusable.
3. Follow Prompts:
   SpyHunter might prompt you to reboot the computer to finalize the removal process. Follow these prompts carefully.

Step 4: Post-Removal Verification

1. Rescan Your System:
   After the initial removal, run another full system scan with SpyHunter to ensure that no remnants of FOX ransomware or associated files remain.
2. Check Critical Files:
   Verify that your critical files are accessible (noting that the encrypted files from the attack will remain encrypted unless you have a backup or a working decryption tool).

Step 5: Additional Cleanup

1. Registry and Startup Entries:
   Some ransomware leaves behind registry entries or scheduled tasks to reinitiate itself. Use SpyHunter’s tools or a trusted registry cleaner to check and remove any suspicious entries.
2. Update All Software:
   Ensure that your operating system, security software, and all applications are up-to-date to prevent future vulnerabilities.

Step 6: Final Precautions

1. Backup Your Data:
   After cleanup, back up your important files to an external drive or cloud storage. Ensure that the backup is not continuously connected to the system to prevent future infections.
2. Monitor System Behavior:
   Keep an eye on your system for any unusual behavior. A follow-up scan with SpyHunter after a few days is recommended to confirm that the threat has been completely eradicated.

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Preventive Measures to Avoid Future Ransomware Infections

While removal tools like SpyHunter are effective, prevention remains the best defense against ransomware like FOX. Here are some proactive measures:

Strengthen RDP Security

• Disable Unused RDP: If Remote Desktop Protocol (RDP) is not needed, disable it to minimize attack vectors.
• Use Strong, Unique Passwords: Ensure that any remote access services are secured with strong, complex passwords. Consider using multi-factor authentication (MFA) where available.
• Limit IP Access: Restrict RDP access to specific IP addresses or use a VPN to secure remote connections.

Keep Software Updated

• Regular Patching: Install updates and patches for your operating system, applications, and firmware as soon as they are available to reduce vulnerabilities.
• Antivirus and Antimalware Software: Keep your security software up-to-date. Many modern antivirus tools include real-time protection against ransomware.

Backup Your Data

• Regular Backups: Perform regular backups of your critical data. Use both on-site and off-site storage solutions.
• Offline Backups: Maintain at least one backup copy offline, as offline backups are immune to ransomware attacks that spread through network connections.

Educate and Train Users

• Email Safety: Train users to recognize phishing attempts and avoid opening suspicious email attachments or links.
• Security Awareness: Regularly update your team or family members on the latest cybersecurity threats and safe browsing practices.

Implement Network Security Measures

• Firewall Configuration:
  Ensure your firewall is properly configured to block unauthorized access.
• Intrusion Detection Systems (IDS):
  Deploy IDS/IPS solutions to detect and prevent suspicious network activities.

Limit Software Installation

• Application Whitelisting: Allow only approved and verified applications to run on your system. This limits the chances of inadvertently executing malicious software.
• Avoid Pirated Software: Download software only from trusted sources. Pirated software is often a vector for malware infections, including ransomware.

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Conclusion

FOX ransomware represents a significant threat due to its aggressive encryption methods, rapid distribution through multiple channels, and the pressure it exerts on victims with its ransom notes. Its integration into the Dharma family means that many of its operational tactics—such as disabling defenses, persistent installation, and rapid file encryption—are designed to maximize damage and minimize the chance of recovery without a decryption key.

The detailed guide provided above illustrates how to effectively remove FOX ransomware using SpyHunter, including downloading, scanning, quarantining, and verifying removal. However, while these removal steps are critical, prevention remains paramount. Strengthening security measures around RDP, maintaining updated systems, regular backups, user education, and robust network security all play essential roles in safeguarding against future ransomware attacks.

It is imperative that individuals and organizations not only respond promptly when an infection occurs but also invest in proactive measures to mitigate the risk of such attacks. Ransomware like FOX can lead to significant data loss and financial damage, so understanding both the threat and the tools available to combat it is crucial.