Home Guides Nozelesn ransomware decryptor and removal tool

Nozelesn ransomware decryptor and removal tool

6 min read
0
44,924
Find out what makes the Nozelesn ransomware one of a kind, how it is circulating, and what can be done to try and restore the encrypted hostage data.
  1. What is the Nozelesn ransomware?
  2. Nozelesn ransomware automated removal and data recovery
  3. Nozelesn ransomware manual removal and file recovery
  4. Ransomware Prevention Tips


What is the Nozelesn ransomware?

When the ransomware species called Nozelesn made its debut last summer, it got very little media coverage back then due to limited distribution and few victims. Despite that, analysts did pay attention to the fact it was a well-designed sample with flawless cryptographic implementation. As time went by, the campaign came to a nearly complete halt, only to reemerge in early 2019 with a very special trick backing it. The malady is being dropped onto computers as a second-stage payload in Emotet malware attacks. The latter is a notorious banking Trojan whose evolution started with sensitive information theft and continued with malware delivery. At this point, the combo of the primary infection and secondary component mainly zeroes in organizations, including ones operating in the hospitality sector of economy.

The strain blemishes encrypted files with the .nozelesn extension
The strain blemishes encrypted files with the .nozelesn extension

The peculiar drive-by promotion mechanism relies on spam for the most part. The would-be victims receive emails mimicking something related to their day-to-day activities, depending on the targeted industry. Messages camouflaged as invoices or job applicants’ resumes are most frequently encountered. The attached Microsoft Word document asking the recipient to enable macros is the pivot of the incursion, because it fires up a perpetrating PowerShell script once opened. Then, the just-triggered malicious entity reaches out to a remote server and downloads the Emotet virus, which in its turn pulls in extra malware behind the scenes. Again, the final payload in recent attacks is the Nozelesn ransomware. When inside and running, the blackmail infection traverses the computer’s hard disks and removable drives in search of important data belonging to the victim. Every item found is subject to uncrackable encryption, with another noticeable byproduct being the concatenation of the .nozelesn extension to the original filename.

Nozelesn virus drops a ransom note named HOW_TO_FIX_NOZELESN_FILES.htm
Nozelesn virus drops a ransom note named HOW_TO_FIX_NOZELESN_FILES.htm

Having completed the unauthorized cryptographic job and having stained all the hostage files on the outside as described above, the Nozelesn virus provides the victim with a way to recover the skewed data. To this end, it drops a rescue note named HOW_FIX_NOZELESN_FILES.htm into encrypted folders. This document contains a typical ransom warning and emphasizes from the get-go that “file decryption costs money”. The user is instructed to download and install Tor browser and enter a specific URL in the address bar, which leads to a page called “Nozelesn decryption cabinet”. There is a login form where the victim is supposed to enter their unique personal code from the ransom note and type a Captcha. Once the authentication is performed, the page says the decryption key costs 0.1 BTC, an amount of cryptocurrency worth about 500 USD. For payment confirmation, the victim needs to enter the relevant Bitcoin transaction ID in the “cabinet” and click the appropriate button to get the decryptor, if it exists.

In light of the possible loss of valuable data, paying the ransom might look like the lesser of two evils. However, doing so isn’t recommended, and here’s why. First of all, the extortionists may simply ignore their promises and never provide the decryption tool. Secondly, there is an ethical dilemma in every such scenario – submitting the payment means giving the malefactors additional resources to move on with their dirty business. Anyway, if the Nozelesn ransomware has infected a computer or enterprise network, the first thing to do is try every alternative data restoration method imaginable.

Nozelesn ransomware automated removal and data recovery

When faced with ransomware like Nozelesn, one of the best shortcuts in terms of removal is to use Combo Cleaner, a lightweight and incredibly effective application with PC security and optimization features under the hood. It detects and thoroughly deletes threats while giving you insights into the overall health of your computer.

This program’s protection power spans modules that forestall all known types of malware, including ransomware and browser hijackers, and take your online security to the next level by blocking phishing sites and other suspicious web pages. Follow these simple steps to eliminate the infection for good:

1. Download Combo Cleaner installer.

Download Nozelesn remover

Combo Cleaner scans your PC with no strings attached, but you’ll have to buy its fully functional version to remove the threats it detects. The disk optimization tools that find large files and duplicates are free to use.

Download and run Combo Cleaner installer on your PC

2. Open the CCSetup.exe file to get started. Several subsequent screens will allow you to make initial customizations so that the program works exactly as you need from the get-go.Setup customizations

3. The installation will be followed by an update of malware signatures. Once this process is through, click the Start Scan button in the left-hand sidebar.Start initial scan

4. Combo Cleaner will then check system locations that are most often polluted by Windows malware. The first scan can take a while to finish.Combo Cleaner scan in progress

5. Combo Cleaner will display a system tray notification as soon as the scan is over. Click the Resolve found threats button to view the results.Scan completed

6. The scan summary shows the names and types of the detected threats as well as their statuses and locations. Click the Remove all threats button and follow further on-screen prompts to get rid of these items.Scan results

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

Nozelesn 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 Nozelesn 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 Nozelesn ransomware using Safe Mode with Networking

Remove Nozelesn ransomware using Safe Mode with Networking

Get rid of Nozelesn ransomware using System Restore

Get rid of Nozelesn 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 .nozelesn 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 Nozelesn 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 Nozelesn 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 Nozelesn removal tool

Rate article

2.33/5 (3)

Leave a Reply

Your email address will not be published. Required fields are marked *