Remove NNUZ Ransomware Virus (DECRYPT .nnuz FILES)

remove NNUZ ransomware virus and learn how to decrypt or repair files with .nnuz extension (free guide)

NNUZ ransomware appears to be the new version of STOP/DJVU computer virus

Contents

NNUZ ransomware appears to be the new version of STOP/DJVU computer virus
How ransomware-type viruses are distributed
Remove NNUZ Ransomware Virus and Decrypt Your Files
Decrypt NNUZ files
Frequently Asked Questions

NNUZ ransomware is a malicious computer virus which aims to encrypt all files in computers that it manages to compromise. Its traits point that it is a variant of STOP/DJVU ransomware which is distinguished from the .nnuz extension it uses to mark encrypted files. For instance, a file originally called 1.jpg appears as 1.jpg.nnuz after the cyber attack, 2.docx appears as 2.docx.nnuz and so on. The primary goal of data encryption is to extort the computer user who now has lost access to all personal files.

Once the ransomware renders all data useless, it immediately offers the victim a “solution.” The virus saves _readme.txt ransom notes in every data folder, and this note explains that the computer user can still recover all data, however, one needs a special decryption software and key. The criminals demand purchasing NNUZ file decryption tools for a large amount of money, and this is nothing else but a pure extortion.

What the ransom note tells the victim

The ransom note dubbed _readme.txt first asks for victim’s attention, then reassures that all encrypted data can still be recovered, if only the victim do as asked by the cybercriminals. They recommend writing an email to them using provided email addresses – admin@helpdata.top and supportsys@airmail.cc.

In addition, they advise including victim’s Personal ID (provided at the very end of the ransom note) and attaching one sample of encrypted file to the email. They promise to include a decrypted file version in their response email to prove they can actually restore all files.

However, the ransom note warns not to send files that contain valuable data, since the criminals can refuse to decrypt such files. The point of the test decryption is to reassure the victim that the criminals actually hold tools needed for data recovery, but not to restore files that are valuable to the victim.

Finally, the _readme.txt note includes pricing of the decryption tool. It depends on how quickly the victim writes to the ransomware operators and pays the ransom. Now, if this is accomplished within 72 hours (3 days), the criminals promise to provide a 50% discount on the ransom price and set it to $490. Otherwise, the victim will be asked to pay the full amount which is $980.

No matter the price, the victim will be demanded to pay it using Bitcoin or some other cryptocurrency since such Blockchain-based transactions are more or less untraceable. Naturally, the threat actors do not want to be tracked down by FBI or other law enforcement agencies.

Let us remind you that paying a ransom is not a solution to the problem you’re experiencing. We strongly recommend reading these FBI guidelines to ransomware victims. Remember that paying the ransom doesn’t guarantee data recovery and simply helps the criminals to produce even more malware. On top of that, you might become a target again since the criminals tend to extort victims who are willing to pay up.

Other damages caused to your computer

Samples of recent STOP/DJVU versions including NNUZ virus appear to drop information-stealing Trojans on infected systems. Two specific threats were observed during analysis of these samples – VIDAR and AZORULT. These computer malware variants are well known for their extensive capabilities that include:

Stealing browser-saved passwords, cookies and browsing history, as well as app login credentials;
Stealing cryptocurrency wallets;
Stealing banking information;
Viewing, deleting files on victim’s computer and downloading additional malware to it;
Emails and message conversations.

Collecting such types of information can provide limitless possibilities to the criminals to extort and blackmail the computer user. Therefore, we advise you to remove NNUZ ransomware virus as soon as you notice its presence in your computer and scan the system for additional threats as well. The ideal way of detecting and removing all malware is running an antivirus tool while in Safe Mode with Networking (see the guide provided below). Additionally, we recommend you to download RESTORO (see full review here) to repair virus damage on Windows OS files.

Ransomware Summary

Name	NNUZ Ransomware Virus
Type	Ransomware; Crypto-malware; Virtual Extortion Virus
Family	STOP/DJVU
Encryption type	RSA 2048 + Salsa20
Previous versions	BYYA, ERRZ, DFWE, FDCV, FEFG, NNUZ, QLLN (find full list here)
Version	485th
Extension	.nnuz
Cybercriminal emails	admin@helpdata.top and supportsys@airmail.cc
Additional malware dropped	Azorult or Vidar Trojan
Damage	The ransomware uses encryption to maliciously modify all files on the PC and marks their original names with .nnuz extension. Ransom notes called as _readme.txt will be dropped in every computer folder. This piece of malware usually drags VIDAR Stealer alongside it and also eliminates VSS from the system. On top of that, it tends to modify Windows HOSTS file to restrict computer user’s access to cybersecurity-related websites online.
Ransom note	_readme.txt
Ransom demand	$490-$980 in Bitcoin
Distribution	Victims often download this ransomware along illegal torrent downloads, cracked software, activators, key generators or tools like KMSPico.
Known software cracks to contain this malware	Corel Draw, Tenorshare 4ukey, Adobe Photoshop, Cubase, Adobe Illustrator, Internet Download Manager, Tally, League of Legends.
Detection names	Ransom:Win32/StopCrypt.PAL!MTB (Microsoft), Trojan.Crypt (A) (Emsisoft), HEUR:Trojan-Ransom.Win32.Stop.gen (Kaspersky), Trojan.GenericKD.47850419 (BitDefender), Trojan.MalPack.GS (Malwarebytes), ML.Attribute.HighConfidence (Symantec) see all detection name variations on VirusTotal
Removal	Remove ransomware and related malware from your PC using trustworthy software. To repair virus damage on Windows OS files, consider scanning with RESTORO (secure download link).

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See a screenshot of a data folder containing encrypted files and the ransom note.

How ransomware-type viruses are distributed

Cybercriminals typically distribute ransomware using phishing email spam, drive-by downloads, fake ads, or torrents. Versions of STOP/DJVU such as NNUZ ransomware virus are usually spotted in rogue websites luring potential victims with pirated software versions. Sadly, instead of getting the real deal, the victim launches a ransomware after clicking on the setup file downloaded from such warez or torrent sites.

Victims have reported downloading previous versions of this ransomware strain disguised as Adobe Photoshop/Illustrator, AutoCad, League of Legends, Cubase, Wondershare Filmora, Virtual DJ Pro or other popular software downloads. We strongly advise you to drop the bad habit of searching for pirated software versions and instead visit the official websites for genuine downloads.

Remember that by paying for legitimate software license keys, you support software developers and avoid cybersecurity risks, whereas when trying to bypass these fees you risk exposing your computer to malware and also infringe copyrights of software producers.

Another popular method used to distribute ransomware relies on email spam. Cybercriminals often compose convincing messages pretending to be someone the victim knows (such as colleague or a boss) or has business with, for example, a parcel delivery company or a widely known e-commerce site like Amazon or eBay. These emails are usually hastily written and include an urgent demand to view attached contents.

These email attachments are filled with malicious scripts that download and execute the ransomware on the computer. For this reason, we recommend computer users to stay away from suspicious emails at all costs. Moreover, you should look out for red flags in emails such as unfamiliar greeting lines, typo mistakes or unknown attached file formats.

Finally, victims of STOP/DJVU should not fall for deceptive websites or scammers claiming they know solution for online key file encryption. If you fall for such scam, there are two possible outcomes – you might get scammed financially or you will end up downloading a non-functional decryption tool that contains malware. You should know that the only possible solutions to recover files locked by STOP/DJVU are created by Emsisoft and DiskTuna.

Remove NNUZ Ransomware Virus and Decrypt Your Files

To remove NNUZ Ransomware Virus and related threats from your computer, start by booting the system in Safe Mode with Networking (see the guide provided below). This will start the system with limited processes and functionalities, therefore suspending any active malware processes. Then, run your chosen antivirus solution to eliminate malware components automatically.

Afterward, consider downloading RESTORO to repair virus damage on Windows OS files. Another tip from our team is to change all passwords used on the compromised host due to potential risk that such data was stolen by the VIDAR/AZORULT Trojans during the cyber attack. Finally, consider reporting the incident to local law enforcement agencies.

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Our team recommends removing malware using a professional antivirus software and then using the following tool to repair virus damage to Windows system files:

REPAIR VIRUS DAMAGE TO YOUR COMPUTER

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RESTORO uses AVIRA scanning engine to detect existing spyware and malware. If any are found, the software will eliminate them.

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NNUZ Ransomware Virus Removal Guidelines

Method 1. Enter Safe Mode with Networking

Step 1. Start Windows in Safe Mode with Networking

Before you try to remove NNUZ Ransomware Virus virus, you must start your computer in Safe Mode with Networking. Below, we provide the easiest ways to boot PC in the said mode, but you can find additional ones in this in-depth tutorial on our website – How to Start Windows in Safe Mode. Also, if you prefer a video version of the tutorial, check our guide How to Start Windows in Safe Mode on Youtube.

Instructions for Windows XP/Vista/7 users

First of all, turn off your PC. Then press the Power button to start it again and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. This launches the Advanced Boot Options menu.
Use arrow keys on the keyboard to navigate down to Safe Mode with Networking option and press Enter.

Instructions for Windows 8/8.1/10/11 users

Open Windows Start menu, then press down the Power button. On your keyboard, press down and hold the Shift key, and then select Restart option.
This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Networking. In this case, it is the F5 key.

Step 2. Remove files associated with the virus

Now, you can search for and remove NNUZ Ransomware Virus files. It is very hard to identify files and registry keys that belong to the ransomware virus, Besides, malware creators tend to rename and change them repeatedly. Therefore, the easiest way to uninstall such type of a computer virus is to use a reliable security program such as INTEGO Antivirus, which also includes data recovery software. For virus damage repair, consider using RESTORO.

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Method 2. Use System Restore

In order to use System Restore, you must have a system restore point, created either manually or automatically.

Step 1. Boot Windows in Safe Mode with Command Prompt

Instructions for Windows XP/Vista/7 users

Shut down your PC. Start it again by pressing the Power button and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. You will see Advanced Boot Options menu.
Using arrow keys on the keyboard, navigate down to Safe Mode with Command Prompt option and press Enter.

Instructions for Windows 8/8.1/10/11 users

Launch Windows Start menu, then click the Power button. On your keyboard, press down and hold the Shift key, and then choose Restart option with the mouse cursor.
This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Command Prompt. In this case, press F6 key.

Step 2. Start System Restore process

Wait until system loads and command prompt shows up.
Type cd restore and press Enter, then type rstrui.exe and press Enter. Or you can just type %systemroot%system32restorerstrui.exe in command prompt and hit Enter.
This launches System Restore window. Click Next and then choose a System Restore point created in the past. Choose one that was created before ransomware infection.
Click Yes to begin the system restoration process.

After restoring the system, we recommend scanning the system with antivirus or anti-malware software. In most cases, there won't be any malware remains, but it never hurts to double-check. In addition, we highly recommend checking ransomware prevention guidelines provided by our experts in order to protect your PC against similar viruses in the future.

Alternative software recommendations

Malwarebytes Anti-Malware

Removing spyware and malware is one step towards cybersecurity. To protect yourself against ever-evolving threats, we strongly recommend purchasing a Premium version of Malwarebytes Anti-Malware, which provides security based on artificial intelligence and machine learning. Includes ransomware protection. See pricing options and protect yourself now.

System Mechanic Ultimate Defense

If you're looking for an all-in-one system maintenance suite that has 7 core components providing powerful real-time protection, on-demand malware removal, system optimization, data recovery, password manager, online privacy protection and secure driver wiping technology. Therefore, due to its wide-range of capabilities, System Mechanic Ultimate Defense deserves Geek's Advice approval. Get it now for 50% off. You may also be interested in its full review.

Disclaimer. This site includes affiliate links. We may earn a small commission by recommending certain products, at no additional cost for you. We only choose quality software and services to recommend.

Decrypt NNUZ files

Fix and open large NNUZ files easily:

It is reported that STOP/DJVU ransomware versions encrypt only the beginning 150 KB of each file to ensure that the virus manages to affect all files on the system. In some cases, the malicious program might skip some files at all. That said, we recommend testing this method on several big (>1GB) files first.

Create a copy of encrypted file to a separate folder using Copy > Paste commands.
Now, right-click the created copy and choose Rename. Select the NNUZ extension and delete it. Press Enter to save changes.
In the prompt asking whether you want to make the changes as file might become unusable, click OK.
Try opening the file.

STOP/DJVU decryption tool usage guide

STOP/DJVU ransomware versions are grouped into old and new variants. NNUZ Ransomware Virus is considered the new STOP/DJVU variant, just like BYYA, ERRZ, DFWE, FDCV, FEFG, NNUZ, QLLN (find full list here). This means full data decryption is now possible only if you have been affected by offline encryption key. To decrypt your files, you will have to download Emsisoft Decryptor for STOP DJVU, a tool created and maintained by a genius security researcher Michael Gillespie.

Note! Please do not spam the security researcher with questions whether he can recover your files encrypted with online key - it is not possible.

In order to test the tool and see if it can decrypt NNUZ files, follow the given tutorial.

Download the decryption tool from Emsisoft.
Click the little arrow next to your download and choose Show in Folder.
Now, right-click the file and choose Run as Administrator. If asked, enter administrator's password.
In UAC window, click Yes.
Click Yes to agree to software terms in both windows.
The tool will automatically include C:// disk as a location to decrypt. The file recovery tool will prepopulate the locations to scan, including connected data storage drives or network drives. Click Add folder if you wish to add additional locations.
In Options tab, you can choose to keep encrypted file copies. We recommend leaving this option selected, especially if you do not know if the decryption tool will work.
Click Decrypt to start restoring NNUZ files. You will see the progress in the Results tab. Here, you can see messages from the tool, such as whether the decryption procedure is successful, or you need to wait for an update.
You might also be informed that online key was used to encrypt your files. In such case, the decryption tool won't work for you, and the only way to recover your files is to use a data backup.

Meanings of decryptor's messages

The NNUZ decryption tool might display several different messages after failed attempt to restore your files. You might receive one of the following messages:

Error: Unable to decrypt file with ID: [example ID]

This message typically means that there is no corresponding decryption key in the decryptor's database.

No key for New Variant online ID: [example ID]
Notice: this ID appears to be an online ID, decryption is impossible

This message informs that your files were encrypted with online key, meaning no one else has the same encryption/decryption key pair, therefore data recovery without paying the criminals is impossible.

Result: No key for new variant offline ID: [example ID]
This ID appears to be an offline ID. Decryption may be possible in the future.

If you were informed that an offline key was used, but files could not be restored, it means that the offline decryption key isn't available yet. However, receiving this message is extremely good news, meaning that it might be possible to restore your NNUZ extension files in the future. It can take a few months until the decryption key gets found and uploaded to the decryptor. We recommend you to follow updates regarding the decryptable DJVU versions here. We strongly recommend backing up your encrypted data and waiting.

Report Internet crime to legal departments

Victims of NNUZ Ransomware Virus should report the Internet crime incident to the official government fraud and scam website according to their country:

In the United States, go to the On Guard Online website.
In Australia, go to the SCAMwatch website.
In Germany, go to the Bundesamt für Sicherheit in der Informationstechnik website.
In Ireland, go to the An Garda Síochána website.
In New Zealand, go to the Consumer Affairs Scams website.
In the United Kingdom, go to the Action Fraud website.
In Canada, go to the Canadian Anti-Fraud Centre.
In India, go to Indian National Cybercrime Reporting Portal.
In France, go to the Agence nationale de la sécurité des systèmes d’information.

If you can't find an authority corresponding to your location on this list, we recommend using any search engine to look up "[your country name] report cyber crime". This should lead you to the right authority website. We also recommend staying away from third-party crime report services that are often paid. It costs nothing to report Internet crime to official authorities.

Another recommendation is to contact your country's or region’s federal police or communications authority.

Frequently Asked Questions

✓ How can I open .NNUZ files?

You can only open NNUZ files if you have the decryption key, or if you were affected by offline encryption type.

✓ How do I know if my files were encrypted with offline or online encryption?

To figure out whether you were affected by offline encryption, please go to C:/SystemID/PersonalID.txt and see if the string inside of it ends in t1. You can also try using Emsisoft Decryptor for STOP/DJVU.

✓ My files contain very important information (family memories). Every tool I used says it is impossible to decrypt. What should I do?

Please follow the guidances provided by the official NNUZ decryption tools and believe what they say. If they say it is impossible to decrypt, it really is so. There is no magic tool or human capable of decrypting your files hiding somewhere. Encryption is a technique created to be nearly impossible to decrypt without a special private key (held by the criminals).

✓ I am afraid virus is still in my computer system. What should I do?

We advise scanning with anti-virus, anti-malware, malware removal tools or software like RESTORO to eliminate virus damage on the system. If you do not trust using a single tool, try running one after another. However, we do not recommend keeping several security programs on a computer at once as they can interfere with each other's work.

✓ I saw several Youtube videos suggesting secret decryption tools. Can I trust them?

Beware of fake NNUZ decryption tools circulating around the web. Cyber criminals are uploading them to various shady websites, also might be promoting them via suspicious Youtube videos. These programs can infect your computer even more heavily (Trojans, miners, etc.). We suggest being extremely cautious around the web. If there will be an official STOP/DJVU decryption tool available, it will be widely discussed in public media.

Norbert Webb

Norbert Webb is the head of Geek’s Advice team. He is the chief editor of the website who controls the quality of content published. The man also loves reading cybersecurity news, testing new software and sharing his insights on them. Norbert says that following his passion for information technology was one of the best decisions he has ever made. “I don’t feel like working while I’m doing something I love.” However, the geek has other interests, such as snowboarding and traveling.