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The Daily Insight

Npsg Virus Removal + Decrypt .npsg Files

Author

Ava White

Updated on March 13, 2026

What is “Npsg”?

Ransomware is a kind of virus that crypted your documents and then forces you to pay to restore them. DJVU (aka STOP) ransomware family was first revealed and discovered by virus analyst Michael Gillespie">2.

Npsg is basically similar to other ransomware like: Btos, Reha, Topi. It crypted all common file types. Hence, users cannot open the your documents or photos. Npsg adds its particular “.npsg” extension into all files. For example, the file “video.avi”, will be changed into “video.avi.npsg”. As soon as the encryption is successfully accomplished, Npsg creates a specific file “_readme.txt” and adds it into all folders that contain the modified files.

Ransomware family3DJVU/STOP4 ransomware
Extension.npsg
Ransomware note_readme.txt
RansomFrom $490 to $980 (in Bitcoins)
Contact,
Detection5Trojan.Downloader.Dofoil, Win32/Injector.EKEL, Trojan.VBInject
SymptomsMost of your files (photos, videos, documents) have a .npsg extension and you can’t open it
Fix Tool GridinSoft Anti-MalwareSee If Your System Has Been Affected by .npsg file virus

This text asking payment is for get files back via decryption key:

Npsg virus message

The scary alert demanding from users to pay the ransom to decrypt the compromised data contains these frustrating warnings

The cryptography algorithm used by Npsg is AES-256. So, if your files got encrypted with a specific decryption key, which is totally and there are no other copies. The sad reality is that it is impossible to restore the information without the unique key available.

In case if Npsg worked in online mode, it is impossible for you to gain access to the AES-256 key. It is stored on a distant server owned by the criminals who distibute the Npsg infection.

For receiving decryption key the payment should be $980. To obtain the payment details the victims are encouraged by the message to contact the frauds by email (), or via Telegram.

Do not pay for Npsg!

_readme.txt file also indicates that the computer owners must get in touch with the Npsg representatives during 72 hours starting from the moment of files where crypted. On the condition of getting in touch within 72 hours users will be granted a 50% rebate, thus the ransom amount will be minimized down to $490). Yet, stay away from paying the ransom!

Also, it may be a good idea to stay away from contacting fraudsters via e-mail. The ransomware distributors may start a friendly talk with you, than force you to pay using social engineering, menacing to stop contacting with you, or even to delete files from your PC giving some miraclous command to ransomware. Even worse, they can add your e-mail in the database and then sold it to another fraudsters or spammers, who will bum you up with another portion of spam.

I definitely advise that you do not contact these crooks and do not pay. The one of the most real working solution to recover the lost data – just using the available backups, or use Decrypter tool.

The peculiarity of all such viruses apply a similar set of actions for generating the unique decryption key to recover the ciphered data.

Thus, unless the ransomware is still under the stage of development or possesses with some hard-to-track flaws, manually recovering the ciphered data is a thing you can’t really perform. The only solution to prevent the loss of your valuable data is to regularly make backups of your crucial files.

Note that even if you do maintain such backups regularly, they ought to be put into a specific location without loitering, not being connected to your main workstation.

For instance, the backup may be kept on the USB flash drive or some alternative external hard drive storage. Optionally, you may refer to the help of online (cloud) information storage.

Needless to mention, when you maintain your backup data on your common device, it may be similarly ciphered as well as other data.

For this reason, locating the backup on your main device is surely not a wise idea.

Little advice : quite often Npsg ransomware is not able to encrypt large-sized files, so such files are getting .npsg extension without real encrypting. So, if you have some important big files, you can try just to delete .npsg extensions from their names, and get access to your files back.

How I was infected?

Npsg virus attack

Npsg attack following a successful phishing attempt.

Nevertheless, these are the common leaks through which it may be injected into your PC:

  • hidden installation along with other apps, especially the utilities that work as freeware or shareware;
  • dubious link in spam emails leading to the Npsg installer
  • online free hosting resources;
  • using illegal peer-to-peer (P2P) resources for downloading pirated software.

There were cases when the Npsg virus was disguised as some legitimate tool, for example, in the messages demanding to initiate some unwanted software or browser updates. This is typically the way how some online frauds aim to force you into installing the Npsg ransomware manually, by actually making you directly participate in this process.

All ransomwares have one common feature : majority of them are distributed in bundle with another malware. It can be whatever – simple adware, annoying browser hijacker, keylogger of even trojan. So, if you detected some malware activity on your computer, don’t shelve a full scan with anti-malware software.

Surely, the bogus update alert will not indicate that you are going to actually inject the Npsg ransomware. This installation will be concealed under some alert mentioning that allegedly you should update Adobe Flash Player or some other dubious program whatsoever.

Of course, the cracked apps represent the damage too. Using P2P is both illegal and may result in the injection of serious malware, including the Npsg ransomware.

To sum up, what can you do to avoid the injection of the Npsg ransomware into your device? Even though there is no 100% guarantee to prevent your PC from getting damaged, there are certain tips I want to give you to prevent the Npsg penetration. You must be cautious while installing free software today.

Make sure you always read what the installers offer in addition to the main free program. Stay away from opening dubious email attachments. Do not open files from the unknown addressees. Of course, your current security program must be always updated.

The malware does not speak openly about itself. It will not be mentioned in the list of your available programs. However, it will be masked under some malicious process running regularly in the background, starting from the moment when you launch your PC.

The message by the Npsg ransomware states the following frustrating information:

ATTENTION! Don't worry, 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. This software will decrypt all your encrypted files. What guarantees you have? You can send one of your encrypted file from your PC and we decrypt it for free. But we can decrypt only 1 file for free. File must not contain valuable information. You can get and look video overview decrypt tool: Price of private key and decrypt software is $980. Discount 50% available if you contact us first 72 hours, that's price for you is $490. Please note that you'll never restore your data without payment. Check your e-mail "Spam" or "Junk" folder if you don't get answer more than 6 hours. To get this software you need write on our e-mail: Reserve e-mail address to contact us: Our Telegram account: @datarestore Mark Data Restore
Your personal ID:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

The image below gives a clear vision of how the files with “.npsg” extension look like:

Npsg Virus - crypted .npsg files

Example of crypted .npsg files

How to remove Npsg virus?

The is an excellent way to deal with recognizing and removing threats – using Gridinsoft Anti-Malware. This program will scan your PC, find and neutralize all suspicious processes">7.

Download Removal Tool.

You can download GridinSoft Anti-Malware by clicking the button below:

Download GridinSoft Anti-Malware

Run the setup file.

When setup file has finished downloading, double-click on the setup-antimalware-fix.exe file to install GridinSoft Anti-Malware on your PC.

Run Setup.exe

An User Account Control asking you about to allow GridinSoft Anti-Malware to make changes to your device. So, you should click “Yes” to continue with the installation.

GridinSoft Anti-Malware Setup

Press “Install” button.

GridinSoft Anti-Malware Install

Once installed, Anti-Malware will automatically run.

GridinSoft Anti-Malware Splash-Screen

Wait for the Anti-Malware scan to complete.

GridinSoft Anti-Malware will automatically start scanning your PC for Npsg infections and other malicious programs. This process can take a 20-30 minutes, so I suggest you periodically check on the status of the scan process.

GridinSoft Anti-Malware Scanning

Click on “Clean Now”.

When the scan has finished, you will see the list of infections that GridinSoft Anti-Malware has detected. To remove them click on the “Clean Now” button in right corner.

GridinSoft Anti-Malware Scan Result

How to decrypt .npsg files?

The newest extensions released around the end of August 2019 after the criminals made changes. This includes Btos, Reha, Topi, etc.

As a result of the changes made by the criminals, STOPDecrypter is no longer supported. Tt has been removed and replaced with the Emsisoft Decryptor for STOP Djvu Ransomware developed by Emsisoft and Michael Gillespie.

You can download free decryption tool here: Decryptor for STOP Djvu.

Download and run decryption tool.

Start downloading the decryption tool.

Make sure to launch the decryption utility as an administrator. You need to agree with the license terms that will come up. For this purpose, click on the “Yes” button:

Emsisoft Decryptor - license terms

As soon as you accept the license terms, the main decryptor user interface comes up:

Emsisoft Decryptor - user interface

Select folders for decryption.

Based on the default settings, the decryptor will automatically populate the available locations in order to decrypt the currently available drives (the connected ones), including the network drives. Extra (optional) locations can be selected with the help of the “Add” button.

Decryptors normally suggest several options considering the specific malware family. The currently possible options are presented in the Options tab and can be activated or deactivated there. You may locate a detailed list of the currently active Options below.

Click on the “Decrypt” button.

As soon as yo add all the desired locations for decryption into the list, click on the “Decrypt” button in order to initiate the decryption procedure.

Note that the main screen may turn you to a status view, letting you know of the active process and the decryption statistics of your data:

Emsisoft Decryptor - the decryption statistics

The decryptor will notify you as soon as the decryption procedure is completed. If you need the report for your personal papers, you can save it by choosing the “Save log” button. Note that it is also possible to copy it directly to your clipboard and to paste it into emails or forum messages if you need to do so.

Frequently Asked Questions

How can I open “.npsg” files?

npsg files contain important information. How can I decrypt them urgently?

You have advised using GridinSoft Anti-Malware to remove Npsg. Does this mean that the program will delete my encrypted files?

Decrytor did not decrypt all my files, or not all of them were decrypted. What should I do?

What can I do right now?

Video Guide

If the guide doesn’t help you to remove Npsg virus, please download the GridinSoft Anti-Malware that I recommended. Also, you can always ask me in the comments for getting help.

References

  1. Ransomware-type infection:
  2. Twitter:
  3. My files are encrypted by ransomware, what should I do now?
  4. About DJVU (STOP) Ransomware.
  5. Encyclopedia of threats.
  6. GridinSoft Anti-Malware Review from HowToFix site:
  7. More information about GridinSoft products: