NOBU ransomware damage can be repaired using several tools
Contents
NOBU ransomware is the 269th and currently the latest variant of the STOP/DJVU virus. This cryptography-based virus targets Windows computers to encrypt all files on them using RSA algorithm, adds .nobu file extensions to original data names, and finally creates ransom-demanding text notes named as _readme.txt in each encryption-affected folder. The note instructs to write to helpmanager@mail.ch or restoremanager@airmail.cc to get further instructions from the cyber criminals. This malware also known for its abilities to delete Volume Shadow Copies from the system, and installation of additional viruses, such as password-stealing Trojans.
Named after a popular restaurant chain, Nobu virus is considered a new version of STOP/DJVU ransomware which uses exceptionally strong encryption technique that is known to be hard to break. To be precise, it is recognized as a military-grade encryption algorithm. This ransomware restricts access to all of victim’s files (documents, photos, videos, audio files, archives, sheets, databases, and other file formats) using a public key. In order to reverse the encryption, a private .nobu decryption key is required. In order to provide it, cybercriminals demand contacting them and paying a ransom.
Criminals list their conditions in _readme.txt ransom note
The creators of NOBU ransomware aim to swindle money from the victim by saying that paying a ransom is the straightest way to the data decryption key and software. Moreover, they leave instructions on how to decrypt .nobu test file for free in _readme.txt. Their aim is to convince the victim that it is “worth” paying the ransom. However, cybersecurity experts advise against ransom payments, as this might not be the ideal solution leading to data recovery.
The attackers can provide partly functional tools, besides, if you pay, they might try to target you again via various other sources, such as email (sending phishing links or infected attachments). These are just a few reasons why paying a ransom to cybercriminals is a bad idea, not to mention the fact that you would be supporting the cybercrime industry if you meet the criminals’ demands.
The ransom note advises that the victim can get a 50% discount for the initial ransom price. To be eligible for it, the victim has to contact the criminals and pay the ransom within 72 hours from the infection timestamp. Otherwise, the ransom price bounces back to $980. Needless to say, the attackers want to receive the sum in cryptocurrency as this helps to guarantee their privacy.
The criminals are extremely greedy. Clearly, not everyone has such amount of money roaming around, especially in these challenging COVID-19 times. Besides, there are tools that can help you recover after NOBU ransomware attack. Therefore, we do not recommend paying the ransom, no matter the circumstances.
This ransomware version is very similar to the previous ones – such as DARJ DAZX, TYWD, TYCX, TYOS, TYPO, JYWD (find full list here). Every virus is a clone of the previous one, except the file extension used. The criminals also tend to change the contact emails provided in the ransom notes from time to time.
In case your computer has been exposed to this STOP/DJVU malware variant, we firmly advise you to remove NOBU ransomware immediately. In other situations, we may advise you to uninstall the virus manually. However, in this case, we suggest at least finishing the system cleanse with a robust malware removal software, which can help to identify skipped files and delete them automatically. We recommend SYSTEM MECHANIC ULTIMATE DEFENSE – also includes data recovery tool.
You should use a software of your choice for virus removal. It is essential to do it as soon as you can and also start changing passwords for logins saved in your browsers (Chrome, Firefox, others) because of the password-stealer that was installed on your system alongside the ransomware.
| Name | Nobu ransomware virus |
| Type | Ransomware; Crypto-virus; File locker |
| Encryption | RSA cryptography |
| Other versions | EPOR, WEUI, LISP, SGLH |
| Ransom note | _readme.txt |
| Extension | .nobu file |
| Criminal contacts | helpmanager@mail.ch or restoremanager@airmail.cc |
| Ransom demand | $490-$980 |
| Decryption tools | Decrypt .nobu files using Emsisoft decryptor for STOP/DJVU, repair using Media_Repair or use data backups |
| Distribution | Infected illegal downloads (torrents), deceptive websites, email spam (malicious attachments and links) |
| Removal | Remove virus using SYSTEM MECHANIC ULTIMATE DEFENSE |
Scan your system for FREE to detect security, hardware and stability issues. You can use the scan results and try to remove threats manually, or you can choose to get the full version of software to fix detected issues and repair virus damage to Windows OS system files automatically. Includes Avira spyware/malware detection & removal engine.
Avoid ransomware infections
NOBU ransomware typically awaits in illegal downloads. Criminals tend to disguise it as an .exe format crack or keygen that travels alongside various software or game torrents. Computer users tend to download them hoping to access premium software versions for free. Sadly, such techniques can attract various malware infections only.
Security experts recommend keeping distance from such download sources and choosing legitimate ways to access premium software licenses. Besides, paying for a legitimate software license is always cheaper than paying a ransom for greedy cybercriminals.
To avoid getting infected with ransomware in general, there are several golden rules you should follow:
- Never open links or attachments that arrive with suspicious email messages. Stay away from them even if they claim to be from legitimate companies such as DPD or DHL, especially if you did not expect for such email to arrive.
- Avoid clicking on online pop-ups suggesting “updates” for software you have on your computer. For example, criminals tend to disguise various malware as fake Adobe Flash Player updates.
- Always keep an up-to-date antivirus software with real-time protection running on your computer.
The most important advice we can give regarding protection against ransomware attacks is to create data backups regularly. These backups should be created and stored on external data storage devices. This means that once you finish creating a backup on such drive, you should eject the drive and store it in a secure location. This way, in case your computer gets infected, your data backups stays safe.
Guide to Nobu ransomware removal
The most relevant action you should take after getting your computer infected is to remove Nobu ransomware virus professionally. For this task, you do not need to invite a computer technician, because you can eliminate the virus manually using the instructions we provide. However, it is strongly recommended to use an automatic malware removal software to identify and kill all ransomware components.
We suggest reading the provided NOBU virus removal instructions carefully. You will need to boot your computer in Safe Mode with Networking in order to start deleting virus’ files. Lastly, you should do the following:
- Create a backup of encrypted files. We do not advise removing corrupt files because there is still hope for .nobu file decryption (in the future, especially if offline encryption was used).
- Try to find sources that contain encrypted file original versions. For instance, you may have sent some files to someone via social media or email. You should try to restore them from there.
- Change ALL the passwords for accounts saved in your web browsers. STOP/DJVU variants have a nasty habit of installing Azorult Trojan on computers, which steals all saved credentials and transmits them to criminals.
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Our team recommends a two-step rescue plan to remove ransomware and other remaining malware from your computer, plus repair caused virus damage to the system:
STEP 1. REMOVE AUTOMATICALLY WITH ROBUST ANTIVIRUS
STEP 2. REPAIR VIRUS DAMAGE TO YOUR COMPUTER
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NOBU 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 NOBU 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 NOBU 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. 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 Nobu files
Fix and open large Nobu 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 Nobu 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. NOBU ransomware virus is considered the new STOP/DJVU variant, just like DARJ DAZX, TYWD, TYCX, TYOS, TYPO, JYWD (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 Nobu 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 Nobu 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 Nobu 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 Nobu 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 NOBU 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
You can only open Nobu files if you have the decryption key, or if you were affected by offline encryption type.
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.
Please follow the guidances provided by the official Nobu 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).
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.
Beware of fake Nobu 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 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.
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