Dx31 Ransomware: Understanding the Threat and Removal Guide

In our analysis of malware samples submitted to VirusTotal, Dx31 has been identified as ransomware from the notorious Phobos family. Dx31 exhibits sophisticated tactics, encrypting files, altering filenames, and delivering ransom notes that demand cryptocurrency payments for file decryption.

Dx31 Ransomware Overview

Dx31 operates as a highly destructive ransomware that encrypts user files and appends the “.dx31” extension along with the victim’s ID and an email address to the filenames. The ransomware employs a dual-pronged approach by providing two ransom notes (“info.hta” and “info.txt”) to communicate with the victims.

Actions and Consequences

1. File Encryption: Dx31 encrypts all user files, rendering them inaccessible. For example, “1.jpg” would be renamed to “1.jpg.id[9ECFA84E-3449].[dx31@mail.com].dx31.”
2. Ransom Notes: Victims are presented with ransom notes, instructing them on how to contact the attackers via email at dx31@mail.com. An alternative email address (dx31@usa.com) is provided if there is no response within 24 hours.
3. Ransom Demands: The ransom note demands a payment in Bitcoins for file decryption. The specific ransom amount is not specified, contingent on the victim’s prompt response.
4. Decryption Offer: To establish credibility, attackers offer to decrypt up to 5 files at no cost, subject to conditions regarding file size and content.

Prevention and Detection Names

• Prevention Measures:
  • Regularly backup data to facilitate recovery without succumbing to ransom demands.
  • Implement robust cybersecurity practices and promote user awareness.
  • Exercise caution when opening email attachments or clicking on links, especially from unknown sources.
  • Avoid downloading software from untrustworthy sources and keep software updated.
• Detection Names:
  • Avast: Win32:Phobos-D [Ransom]
  • Combo Cleaner: Trojan.Ransom.PHU
  • ESET-NOD32: A Variant Of Win32/Filecoder.Phobos.C
  • Kaspersky: HEUR:Trojan-Ransom.Win32.Phobos.vho
  • Microsoft: Ransom:Win32/Phobos.PM

Dx31 Ransomware Removal Guide

Step 1: Isolate Infected System

• Disconnect the infected computer from the network to prevent the spread of the ransomware.

Step 2: Document Ransom Note Details

• Record details from the ransom notes, including the provided email addresses and victim ID.

Step 3: Remove Ransomware

• Utilize a reputable antivirus or anti-malware tool to scan and remove the Dx31 ransomware from the system.

Step 4: File Restoration

• Attempt file restoration from backups once the ransomware is removed.

Step 5: Strengthen Security

• Enhance system security by updating software, employing robust passwords, and educating users about cybersecurity best practices.

Step 6: Report Incident

• Report the ransomware incident to local law enforcement and relevant cybersecurity authorities.

Best Practices for Future Prevention

1. Data Backups: Regularly backup essential data to facilitate recovery without resorting to ransom payments.
2. Cybersecurity Practices: Implement robust cybersecurity measures, including firewalls, antivirus software, and intrusion detection systems.
3. User Education: Train users to recognize phishing attempts, avoid unknown attachments, and exercise caution online.
4. Software Updates: Keep operating systems and applications updated to patch vulnerabilities.
5. Network Security: Secure networks with strong passwords and employ multi-factor authentication where possible.

By following these steps and adopting proactive cybersecurity measures, users can mitigate the risks posed by Dx31 ransomware and similar threats. Remember, prevention is key to safeguarding against the evolving landscape of ransomware attacks.