The Nztt virus, also known as a ransomware, belongs to the STOP family. This malware is notorious for file encryption and extortion. Once the Nztt virus gets into a computer, it targets various types of files, such as documents, videos, photos, and more. It changes the file structure and adds the “.nztt” extension to each encrypted file, making them unusable without the decryptor.
Nztt Virus Overview
Nztt
Nztt virus is ransomware that belongs to the DJVU/STOP family. Its primary purpose is to encrypt files that are important to you. Then, this ransomware asks its victims for a ransom fee – ($490 – $980) in Bitcoin.
The Nztt virus is a type of malware that ciphers your files and coerces you into paying for their recovery. This ransomware ciphers various file types. ciphered files are identifiable by a distinct “.nztt” extension. The affected files become impossible to access and use.
After that, the ransomware asks for a file decryption payment in Bitcoin from its victims, that ranges from $490 to $980, depending on the time passed after the attack. In all cases, a text file with ransom payment guidances is named as “_readme.txt“.
Nztt Ransomware works with Salsa20 encryption algorithms to cipher the files. Since Nztt virus utilizes such a strong encryption method, it becomes particularly difficult, if even possible, to find the decryption key without the assistance of the attackers.
Once Nztt malware finishes the encryption, it shows a ransom note to the user, demanding a ransom payment for the decryption key. The ransom note provides instructions on how to pay off the bill and also often contains threats of system wipeout or increased ransom amounts if the demands are not met within a specified timeframe.
I have compiled an all-encompassing list of potential solutions, advice, and methods to neutralize the Nztt malware and recover your files. There are situations where it may be feasible to restore your files, while sometimes, it may be impossible.
Important Note!
It is important to note that paying off the bill is not a guarantee of the successful files recovery. The individuals behind the Nztt virus are not trustworthy. There were the cases where people have paid the ransom, only to be denied by the cybercriminals with the decryption key provision.
Nztt employs a unique key for each victim, with one exception:
- If Nztt fails to connect the command and control server (C2) before starting the encryption process, it it uses offline keys as a fallback option. An offline key is the same for all users, which allows for the decryption of files encrypted by the ransomware.
The Nztt virus bears resemblance to other DJVU ransomware variants such as Wzer, Wzoq, Wzqw, and Wztt. This virus encrypts a wide range of common file types and appends its distinct “.nztt” extension to all files. For instance, a file named “1.jpg” would be altered to “1.jpg.nztt” and “2.png” to “2.png.nztt“.
Upon successful encryption, malware spawns a special text file named “_readme.txt” and places it in every folder containing the encrypted files. It as well adds this file to the desktop, so the victim will not miss the attack even without opening folders.
The image below provides a visual representation of files with the “nztt” extension:
Encrypted Files by STOP/DJVU Ransomware
| Name | Nztt Virus |
| Ransomware familyMy files are encrypted by ransomware, what should I do now?' data-wpel-link="internal" target="_self" rel="follow">1 | DJVU/STOPAbout DJVU (STOP) Ransomware.' data-wpel-link="internal" target="_self" rel="follow">2 ransomware |
| Extension | .nztt |
| Ransomware note | _readme.txt |
| Ransom | From $490 to $980 (in Bitcoins) |
| Contact | [email protected], [email protected] |
| Detection | Win32/Filecoder.Conti.L Virus Removal, Win32:PWSX-gen [Trj] Virus Removal, PWS:Win32/Fareit!MTB Virus Removal |
| Symptoms |
|
| Fix Tool |
To remove possible malware infections, scan your PC:
6-day free trial available. |
This message asking payment is for restore files via decryption key:
_readme.txt (STOP/DJVU Ransomware) – The alarming warning insisting users to pay off the ransom to unlock the encrypted data contains these exasperating cautions.
Nztt ransomware arrives as a set of procedures that are used to carry out different activities on a victim’s computer. One of the first processes being launched is winupdate.exe, a deceptive process that displays a fraudulent Windows update prompt during the attack. That is needed to convince the victim that a sudden PC slowdown is caused by a Windows update.
Meanwhile, the ransomware runs another process (which name commonly consists of 4 random characters) which starts scanning the computer for target files and ciphering them. Next, the ransomware removes Volume Shadow Copies from the disk using the following CMD command:
vssadmin.exe Delete Shadows /All /Quiet
Once erased, it becomes impossible to retrieve the previous computer state using System Restore Points. The issue is, ransomware operators are getting rid of any built-in Windows approaches that could assist the victim to restore files for free. In addition, the rascals modify the Windows HOSTS file by including a list of domains to it and directing them to the localhost IP. As a result, the victim will see a DNS_PROBE_FINISHED_NXDOMAIN error when accessing one of the listed websites.
It has come to our attention that ransomware attempts to restrict websites that developed various how-to guides for computer users. It is clear that by hindering specific domains, the perpetrators are seeking to hinder the victim from reaching relevant and helpful ransomware-attack-related information online. Malware also stores two .txt files on the victim’s computer that provide attack-related particulars – the public key of this victim and personal ID. These two files are named bowsakkdestx.txt and PersonalID.txt.
After all these alterations, the malware doesn’t stop. Variants of STOP/DJVU have a tendency to release Vidar password-stealing Trojan on compromised systems. This threat has an huge list of capabilities, including:
- Infiltrating the victim’s computer with malware and executing it to gain unauthorized access.
- Obtaining unauthorized access to login credentials of Steam, Telegram, and Skype.
- Manipulating and viewing files on the victim’s computer without their knowledge.
- Stealing cryptocurrency wallets from the victim’s system.
- Granting the hackers remote control over the victim’s computer for various malicious activities.
- Extracting sensitive information such as browser cookies, saved passwords, and browsing history.
The encryption algorithm used by DJVU/STOP virus is AES-256. So, once your data is encrypted with an online decryption key, the chances to get your files back are quite low. Thing is, the key is unique for each victim, and brute forcing it will take exceptionally big amount of time.
Getting the online key in another way is also merely impossible. It is kept on a remote server owned by the crooks who spread the Nztt malware. For receiving decrypting code the payment should be $980. To get the payment details, the victims should contact the hackers by email ([email protected]).
The message by the ransomware states the following 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: https://we.tl/t-WJa63R98Ku 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: [email protected] Reserve e-mail address to contact us: [email protected] Your personal ID: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Do not pay the ransom!
Please, try to use the available backups, or Decrypter tool
_readme.txt file also indicates that the system owners must get in touch with the hackers’ representatives during 72 hours since the file encryption. If user contacts hackers within 72 hours, hackers grant a 50% discount. This decreases the ransom sum down to $490.
Yet, stay away from paying off the ransom! I strongly recommend that you to avoid contacting these swindlers and do not pay. An efficient solution to regain the lost data is just using the available backups, or using Decrypter tool from Emsisoft.
The peculiarity of such malware is the employment a similar set of actions for generating the unique decryption key to recover the ciphered data. Thus, unless the ransomware is still in development or possesses with some hard-to-track flaws, manual data recovery is a thing you can’t perform. The exclusive resolution to prevent the loss of your valuable data is to regularly make backups of your critical files.
Remember that even if you do preserve such backups regularly, they should be stored 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. Alternatively, you may refer to the help of online (cloud) information storage.
Needless to say, when you keep your backup on your common device, it may be similarly ciphered as well as other data. For this reason, placing the backup on your computer’s disk is surely not a wise idea.
How I was infected?
Ransomware has a various methods to built into your system. But it doesn’t really matter what way had place in your case.
Ransomware attack following a successful phishing attempt.
- Concealing the virus within seemingly legitimate apps, especially utilities provided as freeware or shareware.
- Spreading the virus through spam emails containing suspicious links that lead to the virus installer.
- Exploiting online free hosting resources to host and distribute the virus files discreetly.
- Obtaining pirated software from illegal peer-to-peer (P2P) resources, which may unknowingly contain malware.
Some incidents occurred when the Nztt virus was disguised as a legit tool, for example, the messages requesting to install a browser update or a vastly needed codec for online media playback. This is commonly the way how some online scams aim to force you into installing the ransomware manually, by actually making you directly participate in this process.
Surely, the fraudulent update alert will not indicate that you are installing the threat. This process will be disguised under some alert stating that you must install an urgent security update or some suspicious program whatsoever.
Certainly, the software cracks represent the damage as well. Using P2P is both illegal and may end up with the injection of serious malware, including the Nztt ransomware.
To sum up, what can you do to evade the injection of the ransomware into your computer? Even though there is no 100% assurance to thwart your PC from getting compromised, there are some tips I want to give you to avert the Nztt penetration. You must be vigilant while setting up free software today.
Ensure you always read what the installer offers aside from the main free program. Stay away from opening suspicious email attachments. Do not open files from the unknown addressees. Certainly, your current anti-malware program must always be updated.
The malware does not show itself openly. It will not be mentioned in the list of your available programs. However, it will be masked under some malevolent process running consistently in the background, that starts at the moment when you boot up your computer.
How To Remove Ransomware?
Remove Nztt Virus with Gridinsoft Anti-Malware
We have also been using this software on our systems ever since, and it has always been successful in detecting viruses. It has blocked the most common Ransomware as shown from our tests with the software, and we assure you that it can remove Nztt Virus as well as other malware hiding on your computer.
To use Gridinsoft for remove malicious threats, follow the steps below:
1. Begin by downloading Gridinsoft Anti-Malware, accessible via the blue button below or directly from the official website gridinsoft.com.
2.Once the Gridinsoft setup file (setup-gridinsoft-fix.exe) is downloaded, execute it by clicking on the file.
3.Follow the installation setup wizard's instructions diligently.
4. Access the "Scan Tab" on the application's start screen and launch a comprehensive "Full Scan" to examine your entire computer. This inclusive scan encompasses the memory, startup items, the registry, services, drivers, and all files, ensuring that it detects malware hidden in all possible locations.
Be patient, as the scan duration depends on the number of files and your computer's hardware capabilities. Use this time to relax or attend to other tasks.
5. Upon completion, Anti-Malware will present a detailed report containing all the detected malicious items and threats on your PC.
6. Select all the identified items from the report and confidently click the "Clean Now" button. This action will safely remove the malicious files from your computer, transferring them to the secure quarantine zone of the anti-malware program to prevent any further harmful actions.
8. If prompted, restart your computer to finalize the full system scan procedure. This step is crucial to ensure thorough removal of any remaining threats. After the restart, Gridinsoft Anti-Malware will open and display a message confirming the completion of the scan.
Remember Gridinsoft offers a 6-day free trial. This means you can take advantage of the trial period at no cost to experience the full benefits of the software and prevent any future malware infections on your system. Embrace this opportunity to fortify your computer's security without any financial commitment.
Trojan Killer for "Nztt Virus" removal on locked PC
In situations where it becomes impossible to download antivirus applications directly onto the infected computer due to malware blocking access to websites, an alternative solution is to utilize the Trojan Killer application.
There is a really little number of security tools that are able to be set up on the USB drives, and antiviruses that can do so in most cases require to obtain quite an expensive license. For this instance, I can recommend you to use another solution of GridinSoft - Trojan Killer Portable. It has a 14-days cost-free trial mode that offers the entire features of the paid version. This term will definitely be 100% enough to wipe malware out.
Trojan Killer is a valuable tool in your cybersecurity arsenal, helping you to effectively remove malware from infected computers. Now, we will walk you through the process of using Trojan Killer from a USB flash drive to scan and remove malware on an infected PC. Remember, always obtain permission to scan and remove malware from a computer that you do not own.
Step 1: Download & Install Trojan Killer on a Clean Computer:
1. Go to the official GridinSoft website (gridinsoft.com) and download Trojan Killer to a computer that is not infected.
2. Insert a USB flash drive into this computer.
3. Install Trojan Killer to the "removable drive" following the on-screen instructions.
4. Once the installation is complete, launch Trojan Killer.
Step 2: Update Signature Databases:
5. After launching Trojan Killer, ensure that your computer is connected to the Internet.
6. Click "Update" icon to download the latest signature databases, which will ensure the tool can detect the most recent threats.
Step 3: Scan the Infected PC:
7. Safely eject the USB flash drive from the clean computer.
8. Boot the infected computer to the Safe Mode.
9. Insert the USB flash drive.
10. Run tk.exe
11. Once the program is open, click on "Full Scan" to begin the malware scanning process.
Step 4: Remove Found Threats:
12. After the scan is complete, Trojan Killer will display a list of detected threats.
13. Click on "Cure PC!" to remove the identified malware from the infected PC.
14. Follow any additional on-screen prompts to complete the removal process.
Step 5: Restart Your Computer:
15. Once the threats are removed, click on "Restart PC" to reboot your computer.
16. Remove the USB flash drive from the infected computer.
Congratulations on effectively removing Nztt Virus and the concealed threats from your computer! You can now have peace of mind, knowing that they won't resurface again. Thanks to Gridinsoft's capabilities and commitment to cybersecurity, your system is now protected.
Video Guide
How To Decrypt .nztt Files?
How to restore big files?
Try deleting .nztt extension on a few big files and opening them. This malware has issues with large files encryption. Either the virus accessed and did not encode the file, or it failed and did not add the filemarker. If your files are very large (2GB+), such a situation is highly probable. Please, text me in the comments whether this helped you or not.
The newest extensions released around the end of August 2019 after the criminals made changes. This includes Wzer, Wzoq, Wzqw etc.
As a result of the alterations made by the criminals, STOPDecrypter is no longer supported. It has been replaced with the Emsisoft Decryptor for STOP Djvu Ransomware developed by Emsisoft.
You can download free decryption tool here: Decryptor for STOP Djvu.
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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:
As soon as you accept the license terms, the main decryptor user interface comes up:
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Select folders for decryption.
Based on the default configurations, the decryptor will by default choose the accessible directories in order to decode the currently available drives (the connected ones), including the network drives. Additional (optional) locations can be selected with the help of the “Add” button.
Decryptors usually offer several options considering the specific malware family. The existing possible options are displayed in the Options tab and can be enabled or turned off there. You may find a comprehensive list of the currently active Options below.
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Click on the “Decrypt” button.
As soon as you 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:
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 messages here if you need to do so.
The Emsisoft Decryptor might display different messages after a failed attempt to restore your files:
✓ Error: Unable to decrypt file with ID: [your ID]
✓ No key for New Variant online ID: [your ID]
Notice: this ID appears to be an online ID, decryption is impossible
✓ Result: No key for new variant offline ID: [example ID]
This ID appears be an offline ID. Decryption may be possible in the future.
It can take a few weeks or months until the decryption key gets found and uploaded to the decryptor. Please follow updates regarding the decryptable DJVU versions here.
✓ Remote name could not be resolved
How to Restore .nztt Files?
In some case ransomware is not doom for your files…
The Nztt ransomware encryption mechanism sequence is next: it ciphers every file byte-by-byte, then saves a duplicate, deleting (not overriding!) the initial file. Thus, the data of the file location on the physical disk is lost, but the original file is not removed from the physical disk. The cell, or the sector where this file was stored, can still hold this file, but it is absent in the file system and can be overwritten by data that has been loaded to this disk after the deletion. Hence, it is possible to restore your files using special software.
Anyway, after realizing it was an online algorithm, it is impossible to retrieve my encrypted files. I also had my backup drive plugged in at the time of the virus, and this was also infected, or so I thought. Every folder within my backup drive had been infected and was encrypted. However, despite losing some important files, I retrieved almost 80% of my 2TB storage.
When I started going through the folders, I noticed the readme.txt ransom note in every folder. I opened some of the folders and found that all files that were not in a subfolder within that folder had been encrypted. However, I found a flaw and glimmer of hope when I went into the subfolders in other folders and found that these files had not been encrypted. Every folder within my c and d drives, including subfolders, had been encrypted, but this was not the case with the backup drive. Having subfolders created within a folder has saved 80% of my data.
As I said, I believe this to be only a small loophole on a backup drive. I’ve since found a further 10 % of my data on another hard drive on a different pc. So my advice is if you use a backup drive, create subfolders. I was lucky, I guess. But I was also unlucky that the virus hit as I was transferring some files from my backup.
Hopefully, this can help some other people in my situation.
Jamie NewlandRecovering your files with PhotoRec
PhotoRec is an open-source program, which is originally created for file retrieval from damaged disks, or for files recovery in case if they are unintentionally deleted. However, as time has gone by, this program received the ability to retrieve the files of 400 different formats. Hence, it can be used for data recovery after the Nztt attack.
First, you need to download this app. It is 100% free, but the developer states that there is no guarantee that the files will be recovered. PhotoRec is spread in a pack with other program of the same developer – TestDisk. The downloaded archive will bear TestDisk name, but don’t worry. PhotoRec files are right inside.
To launch PhotoRec, you need to find and open “qphotorec_win.exe” file. No setup is required – this program has all the files it need inside of the archive, hence, you can mount it on your USB drive, and try to help your friends/parents/anyone who has been attacked by Nztt ransomware.
Upon the launch, you will see the screen showing you the complete list of your disk spaces. However, this data is probably futile, because the required menu is placed a bit higher. Click this tab, then choose the disk which was attacked by ransomware.
After choosing the disk, you need to choose the destination folder for the reclaimed files. This menu is located at the lower part of the PhotoRec window. The best choice is to export them on USB drive or any other type of removable disk.
Then, you need to specify the file formats. This setting is located at the bottom, too. As it was mentioned, PhotoRec can regain the files of about 400 different formats.
Finally, you can begin files retrieval by pressing the “Search” button. You will observe the screen where the findings of the scan and recovery are shown.
Nztt files recovery Video Guide.
Frequently Asked Questions
How can I open “.nztt” files?
No way. These files are encrypted by ransomware. The contents of encrypted files are not available until they are decrypted.
Encrypted files contain important information. How can I decrypt them urgently?
If your data remained in the .nztt files are very valuable, then most likely you made a backup copy.
If not, then you can try to restore them through the system function – Restore Point.
All other methods will require patience.
You have advised using GridinSoft Anti-Malware to remove Nztt. Does this mean that the program will delete my encrypted files?
Of course not. Your encrypted files do not pose a threat to the computer. What happened has already happened.
You need GridinSoft Anti-Malware to remove active system infections. The virus that encrypted your files is most likely still active and periodically runs a test for the ability to encrypt even more files. Also, these viruses install keyloggers and backdoors for further malicious actions (for example, theft of passwords, credit cards) often.
This virus has blocked infected PC: I can’t get the activation code.
In this situation, you need to prepare the memory stick with a pre-installed Trojan Killer.
Decryptor did not decrypt all my files, or not all of them were decrypted. What should I do?
Have patience. You are infected with the new version of STOP/DJVU ransomware, and decryption keys have not yet been released. Follow the news on our website.
We will keep you posted on when new keys or new decryption programs appear.
What can I do right now?
The Nztt ransomware encrypts only the first 150KB of files. So MP3 files are rather large, some media players (Winamp for example) may be able to play the files, but – the first 3-5 seconds (the encrypted portion) will be missing.
You can try to find a copy of an original file that was encrypted:
- Files you downloaded from the Internet that were encrypted and you can download again to get the original.
- Pictures that you shared with family and friends that they can just send back to you.
- Photos that you uploaded on social media or cloud services like Carbonite, OneDrive, iDrive, Google Drive, etc
- Attachments in emails you sent or received and saved.
- Files on an older computer, flash drive, external drive, camera memory card, or iPhone where you transferred data to the infected computer.
If the guide doesn’t help you to remove infection, please download the GridinSoft Anti-Malware that I recommended. Do not forget to share your experience in solving the problem. Please leave a comment here! This can help other victims to understand they are not alone. And together we will find ways to deal with this issue.
How to Protect Your Computer from Nztt Ransomware
As cyber threats continue to evolve, ensuring the security of our computers has become more critical than ever. Malware, short for malicious software, poses a significant risk to our data, privacy, and overall online experience. Follow these simple guidelines to protect your computer:
- Install a Reliable Anti-Malware Solution: Having a robust anti-malware software is your first line of defense against cyber threats. Gridinsoft Anti-Malware is an industry-leading solution that offers real-time protection, thorough system scans, and automatic malware removal. Its constantly updated database ensures it can detect even the newest and most sophisticated threats.
- Keep Your Operating System and Software Updated: Regularly updating your operating system and software is crucial. Updates often include security patches that address vulnerabilities that cybercriminals may exploit. Enable automatic updates to ensure you stay protected.
- Exercise Caution with Email Attachments and Links: Malicious emails often contain infected attachments or links that lead to malware-infested websites. Avoid opening suspicious emails or clicking on unknown links. Be especially wary of emails that urge you to take immediate action or provide sensitive information.
- Use Strong Passwords and Enable Two-Factor Authentication: Strong, unique passwords are essential for protecting your online accounts. Enable two-factor authentication (2FA) whenever possible to add an extra layer of security.
This post first appeared on Useful Tips For Finding Viruses On Your Computer. Hope Is Not Lost! Follow Our Guides To Fix Your PC And Get Rid Of A Computer Virus., please read the originial post: here
