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Remove Dutan ransomware and decrypt .dutan file virus

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STOP Djvu ransomware operators have released a new variant that speckles encrypted files with the .dutan extension and drops _readme.txt ransom note.
  1. What is the Dutan ransomware?
  2. Dutan ransomware automated removal and data recovery
  3. Dutan ransomware manual removal and file recovery
  4. Ransomware Prevention Tips


What is the Dutan ransomware?

A ransomware attack isn’t only about putting cryptography to malicious use. It’s also about serious damage incurred by every victim, where every incident is a whole separate story. Some of the infected users run the risk of losing precious digital memories, while others are at their wit’s end finding ways to restore important work documents. The adversaries who masterminded this phenomenon should definitely be ashamed of themselves, but the fact persists that these pests are out there hitting numerous users and organizations every single day. One of the latest ruthless electronic contrivances from this category is referred to as the .dutan file virus based on the extension it appends to hostage data items. It is also identifiable by a peculiar filename of the rescue note being created on a compromised host, namely _readme.txt document that the culprit embeds into every folder with encrypted objects and additionally drops onto the desktop.

Ransom note and encrypted .dutan files in a folder
Ransom note and encrypted .dutan files in a folder

As per behavioral analytics and code properties, it turns out that this sample is a spinoff of a large family dubbed STOP Djvu ransomware. A few specimens from this lineage that gained a great deal of traction earlier include .djvu (.djvuu) and .pdff file versions. As a matter of fact, the crooks in charge of this campaign have been showing unprecedented productivity lately. During the past week alone, they have coined a handful of iterations that stain files with the following extensions: .kiratos, .todarius, .hrosas, .verasto, .moresa, .quvara, .etols, and .norvas, not to mention the edition being described in this post. Obviously, the offending operation is underway and the risk of encountering this strain is higher than ever. When the Dutan ransomware infects a Windows computer, it instantly begins a surreptitious scan of the hard disk, removable drives and network shares in search of files that match its built-in list of popular formats. This way, it spots a vast majority of the victim’s personal and important data that eventually becomes the core element of defiant extortion.

Dutan version of STOP Djvu ransomware drops _readme.txt recovery note
Dutan version of STOP Djvu ransomware drops _readme.txt recovery note

This sample employs a cipher to make it impossible for the victim to access their information the normal way. The biggest change takes place on the invisible inside of the files, where the digital structure of each one gets scrambled to render all regular methods of opening or editing it futile. The outer manifestation of the targeted entities becomes skewed as well, not to such a big extent though. While the original filenames are modified, they get the .dutan string added to them so that a sample document Novel.docx turns into Novel.docx.dutan. The only touchpoint of the malefactors with the plagued user is the decryption manual named _readme.txt, something the victim doesn’t have to spend hours looking for because it appears right within their sight on the desktop as well as inside all directories affected by the crypto virus. Here’s a snippet of the introductory text from this note:

ATTENTION!
Don’t worry my friend, you can return all your files!
All your files like photos, databases, documents and other important are encrypted with strongest encryption and unique key. The only method of recovering files is to purchase decrypt tool and unique key for you.

Notice the hypocrisy in the friendly way that the villains address the victim. Also, the statement about “strongest encryption” doesn’t really hold true, because security analysts and cryptography gurus have managed to crack quite a few versions of the STOP Djvu ransomware. Unfortunately, the .dutan edition isn’t supported by these benign recovery techniques at the time of writing. Anyway, the attackers demand $980 worth of cryptocurrency for their decryptor. Interestingly, they claim to provide a 50% discount if the user reaches out to them within the first 72 hours after the incursion. Speaking of which, the contact email addresses for the .dutan file variant are vengisto@firemail.cc and gorentos@bitmessage.ch. Additionally, the extortionists provide their Telegram account @datarestore in the rescue file. When sending the message, the victim is supposed to insert their personal ID so that the black hats can identify the specific instance.

However, it’s in every affected user’s best interest to avoid dealing with the felons and try every alternative option instead. Not only is this a way to save hundreds of dollars, but it’s also a reasonable refusal to fund the disgusting business. So start the remediation with the steps below and, hopefully, bid farewell to the cyber predators.

Dutan ransomware automated removal and data recovery

When dealing with the Dutan threat, you can get a lot of mileage out of the Malwarebytes automatic security tool that will pinpoint and iron out the infection in minutes. Malwarebytes is one of the big names in the anti-malware industry with an immaculate track record of protecting systems against all prevalent forms of harmful code.

The solution uses artificial intelligence (AI) and machine learning to detect both known and zero-day threats, including potentially unwanted programs (PUPs), ransomware, exploits, and malicious sites. It boasts low system footprint, high scanning speed, and intuitive interface where every module clearly explains what it does. Follow the steps below to come through the malware predicament unscathed:

1. Download and install the latest version of Malwarebytes onto your PC.

As part of this step, you will be prompted to specify where you are installing the program (personal or work computer) and toggle the advanced setup options if you so desire. You can use all the premium features for 14 days free of charge.

Download Dutan virus remover

2. Once the application is up and running, go ahead and click on the Scan button in the bottom middle part of the GUI. Click the Scan button

3. Wait until Malwarebytes checks for updates of its proprietary Katana detection engine and scans the memory, startup items, registry, and file system for threats. Malwarebytes scan in progress

4. When the scan is completed, go over the report listing the infections that have been identified. Make sure there are checkmarks next to all the unwanted items and click on the Quarantine button as shown below. Malwarebytes scan results

5. You will be prompted to restart your computer to finish the removal process. Click Yes to do it immediately or close the dialog and restart later on. Restart to complete the removal process

6. As soon as the threats have been moved to Quarantine, they can no longer harm your computer. If you are sure that you won’t need to restore any of those items at a later point, click on the Detection History pane at the bottom left of the Malwarebytes home screen, select the Quarantined items tab, and click Delete. Delete quarantined items

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

Dutan ransomware manual removal and file recovery

Some ransomware strains terminate themselves after completing the encryption job on a computer, but some don’t. Furthermore, the Dutan virus may prevent victims from using popular antimalware tools in order to stay on board for as long as possible. Under the circumstances, it may be necessary to utilize the Safe Mode with Networking or System Restore functionality.

Remove Dutan ransomware using Safe Mode with Networking

Remove Dutan ransomware using Safe Mode with Networking

Get rid of Dutan ransomware using System Restore

Get rid of Dutan ransomware using System Restore

System Restore enables Windows users to roll back all changes made to the OS since the latest restore point creation time. This feature can help eliminate the most persistent ransomware. Before going this route, though, make sure System Restore had been enabled prior to the breach, otherwise the method will be inefficient.

  • Open Windows Advanced Options Menu as described in the previous section: hit F8 repeatedly when the PC is starting up. Use arrow keys to highlight the Safe Mode with Command Prompt entry. Hit Enter.Safe Mode with Command Prompt
  • In the Command Prompt window, type cd restore and hit Entercd restore command
  • Type rstrui.exe in the new command line and press EnterType rstrui.exe command
  • When the System Restore screen pops up, click Next, select a restore point that predates the contamination, and use the application’s controls to roll back the system to this earlier state.System Restore window

Be advised that even after the ransomware is removed, files will still be encrypted and inaccessible. The malicious code cleanup part, however, is important because it keeps a relapse of the infection from occurring further on and eliminates all opportunistic malware.

Ways of non-ransom recovery of .dutan files

Cracking the crypto used by this ransom Trojan is more of a science fiction thing rather than an attainable prospect for the masses. This is why the troubleshooting in predicaments of this sort is a matter of two approaches: one is to pay the ransom, which isn’t an option for many victims; and the other is to apply instruments that take advantage of the ransomware’s possible weaknesses. If the latter is your pick, the advice below is a must-try.

Backups can make your day

Backups can make your day

Not only are you a lucky person in case you’ve been backing up your most important files, but you’re also a wise and prudent user. This isn’t necessarily a resource-heavy activity these days – in fact, some providers of online services are allocating a sufficient size of cloud storage space for free so that every customer can easily upload their critical data without paying a penny. Having removed the Dutan ransomware, therefore, all you have to do is download your stuff from the remote server or transfer it all from an external piece of hardware if that’s the case.

Restore previous versions of encrypted files

Restore previous versions of encrypted files

A positive upshot of using this technique depends on whether or not the ransomware has erased the Volume Shadow Copies of the files on your PC. This is a Windows feature that automatically makes and keeps the backups of data elements on the hard drive as long as System Restore is enabled. The cryptoware in question is programmed to switch off the Volume Shadow Copy Service (VSS), but it has reportedly failed to in some cases.

Checking one’s options regarding this workaround is doable in two ways: through the Properties menu of each file or by means of the remarkable open-source tool called Shadow Explorer. We recommend the software-based way because it’s automated, hence faster and easier. Just install the app and use its intuitive controls to get previous versions of the encrypted objects reinstated.

Shadow Explorer

Alternatively, you can leverage the Previous Versions feature, which is native to Windows operating system. This method is more cumbersome that the use of ShadowExplorer, but it can help restore the most important individual files on condition that the ransomware failed to disable the Volume Snapshot Service on the computer. Right-click on a file of choice and select Properties. Then, go to the Previous Versions tab as illustrated below.

Previous Versions

Go ahead and pick the file’s latest backup version on the list. Use the Copy or Restore buttons to reinstate this object to a new path or to its original folder, respectively.

Ransomware Prevention Tips

To avoid Dutan 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 Dutan ransomware removal tool

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