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DXXD ransomware: how to decrypt .dxxd files virus

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The ransomware to be dissected in this post encrypts its victims’ files using AES-256 algorithm and appends the dxxd string to the original file extensions.

The DXXD crypto ransomware malady is notoriously intricate. Aside from the customary tactics leveraged by most online extortionists, the individuals running said campaign use more social engineering in their attack routine. For instance, the offending software displays a rogue warning screen before system login that impersonates a message from Microsoft Windows Security Center. Another offbeat feature is that this Trojan merges the “dxxd” array with the original extensions of all enciphered files, with no dots or other separation whatsoever. Therefore, a file named “agenda.docx” will become “agenda.docxdxxd” in the long run. Furthermore, unlike the majority of competing ransomware pests out there, this one has no specially crafted payment page for a victim to visit, submit the ransom and download an automatic decryptor. Instead, all the correspondence is via email.

Encrypted files with the dxxd extension tail
Encrypted files with the dxxd extension tail

Let’s take a closer look at the tactic with the counterfeit legal notice. Having contaminated a Windows Server machine or a regular desktop computer, the DXXD virus modifies a number of system registry keys so that a pre-designed alert shows up before the user gets to the point where they enter their admin credentials. The fake notification reads, “Administrator, your server is attacked by hackers. For more informations [sic] and recommendations, write to our experts by e-mail: shellexec@protonmail.com or null_ptr@tutanota.de.” When the user clicks the OK button underneath, they are able to log into the operating system as they normally do.

Whereas it may appear that the deceptive pre-login alert is actually the only ransom note produced by DXXD, there is a Notepad counterpart thereof on the hard drive. A document called ReadMe.TxT, which ends up on the desktop and inside all folders with personal data, contains basically the same recommendations. Perhaps the only difference is that the victim can alternatively use a messaging client called Pidgin if there is no response over email.

DXXD virus warning on the Windows Server login screen
DXXD virus warning on the Windows Server login screen

An additional hazard associated with the DXXD ransomware is that it can locate and encrypt files on both mapped and unmapped network shares. In other words, if a user keeps important data backups on a network repository that isn’t reflected as a separate drive letter, these files may become encrypted just like everything else stored locally. The expanded attack surface makes this sample more dangerous than most ransom Trojans across the board.

Knowing how this strain circulates can shed light on the applicable prevention methods. It is reportedly distributed over hacked RDP (Remote Desktop Protocol) connections, that is, manually deposited and executed on systems. Some researchers, though, believe this specimen propagates by means of spam or 0day exploits. One way or another, it’s always a good idea to use two-factor authentication with RDP services, abstain from opening untrustworthy email attachments, and make sure the OS and third-party programs are patched as soon as new updates are available.

DXXD ransomware automated removal and data recovery

Owing to an up-to-date database of malware signatures and intelligent behavioral detection, the recommended software can quickly locate the infection, eradicate it and remediate all harmful changes. So go ahead and do the following:

1. Download and install the antimalware tool. Open the solution and have it check your PC for PUPs and other types of malicious software by clicking the Start Computer Scan button

Download DXXD virus remover

2. Rest assured the scan report will list all items that may harm your operating system. Select the detected entries and click Fix Threats to get the troubleshooting completed.

Data recovery toolkit to the rescue

Some strains of ransomware are known to delete the original files after the encryption routine has been completed. As hostile as this activity appears, it can play into your hands. There are applications designed to revive the information that was obliterated because of malfunctioning hardware or due to accidental removal. The tool called Stellar Data Recovery features this type of a capability and therefore it can be applied in ransom attack scenarios to at least get the most important files back. So use the app to get an idea of what data can be restored and let it do the recovery job. Here is a step-by-step walkthrough:

1. Download and install Stellar Data Recovery.

Download Stellar Data Recovery

2. Open the application, select the types of recoverable files to look for, and click Next.Stellar Data Recovery main screen

3. Choose the areas you want the tool to recover from and click the Scan button.Select which PC areas to recover from

4. Having scanned the specified locations, the program will display a notification about the total amount of recoverable data. Close the dialog and click the Recover button. This will hopefully help you get some of your valuable files back.Recover files

Ransomware Prevention Tips

To avoid DXXD ransomware and other file-encrypting infections in the future, follow several simple recommendations:

  • Toggle your email provider’s anti-spam settings to filter out all the potentially harmful incoming messages. Raising the bar beyond the default protection is an important countermeasure for ransom Trojans
  • Define specific file extension restrictions in your email system. Make sure that attachments with the following extensions are blacklisted: .js, .vbs, .docm, .hta, .exe, .cmd, .scr, and .bat. Also, treat ZIP archives in received messages with extreme caution
  • Rename the vssadmin.exe process so that ransomware is unable to obliterate all Shadow Volume Copies of your files in one shot
  • Keep your Firewall active at all times. It can prevent crypto ransomware from communicating with its C&C server. This way, the threat won’t be able to obtain cryptographic keys and lock your files
  • Back up your files regularly, at least the most important ones. This recommendation is self-explanatory. A ransomware attack isn’t an issue as long as you keep unaffected copies of your data in a safe place
  • Use an effective antimalware suite. There are security tools that identify ransomware-specific behavior and block the infection before it can do any harm.

These techniques are certainly not a cure-all, but they will add an extra layer of ransomware protection to your security setup.

Revise your security status

Post-factum assessment of the accuracy component in malware removal scenarios is a great habit that prevents the comeback of harmful code or replication of its unattended fractions. Make sure you are good to go by running an additional safety checkup. Another benefit of using the antimalware tool is that it will keep ransomware threats from intruding on your computer further on.

Download DXXD ransomware removal tool

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