Nosu ransomware (Decryption Methods Included) - Free Guide

What is Nosu ransomware?

Nosu ransomware is the cryptovirus that can encrypt valuable files and transfer other data to remote servers for later use

Nosu ransomware virus is the threat that makes files unreadable by encrypting them. Nosu ransomware – a malware that focuses on encryption, so ransom can get demanded directly from victims. This is a member of the DJVU ransomware family that is known for delivering such viruses for a few years now. The infection triggers additional services and comes in a few phases, so malicious operations continue even after the main event – encryption. This threat can create Windows registry entries, disable functions, install files or programs, and even steal data from the machine. It is common for such threats to disable security programs or system features that can help with virus removal or data recovery processes. Malicious actors who create this threat try to make sure that victims have fewer opportunities to recover from the attack and chooses to pay up, so their data gets restored by the criminals.

Victims of the previous versions had more options for data recovery because researchers offered a few services designed for decryption and file recovery. Unfortunately, STOPDecrypter is no longer supported since Nosu ransomware virus developers changed their encryption coding and the method of generating victims' IDs. Many versions that came out in Summer 2019 go decrypted using common offline keys. Since August of last year, victims cannot get their files back because online keys get employed more often.

There might be a solution for files encrypted by this Nosu files virus, but you need to determine if the ID that is presented in the ransom note file _readme.txt ends in t1 or not. This is important because the recently designed Emsisoft decryption tool offers the service for people whose devices got encrypted by the offline versions – containing the t1 at the end of the identification key. In other cases, the best option is to remove the threat using AV tools and then to recover files using thrid-party companies or data backups from external devices.

Nosu files virus is the threat that aims at users all over the world and targets commonly used files like photos, videos, documents, databases, and archives. The infiltration of the threat starts unnoticed, and quickly after that, encryption is started. Files in needed formats and types get encrypted in minutes, and ransom demand shows up on the screen for the victim.

The money-asking note is not much changed from the first version of the family. Nosu ransomware itself is almost identical to all the threats released before this one because the ransom note file is still named _readme.tx and still delivers the same informational message. The only thing that malicious actors keep on changing is the contact emails. Yet still, this particular threat shares the same contact emails with a few other versions from December.

Nosu ransomware also demands the same amount of money and offers a discount for people who manage to contact criminals in the first 72 hours. That is not recommended to do, however.^[1] Noone in the field of cybersecurity can state that contacting or paying these criminals is a positive action. Nosu ransomware shows the ransom-demand message in a text file that also includes contact information of the criminals. You may end up contacting criminals and getting more malware in return instead of Nosu ransomware removal or decryption software. There is no need to even consider paying criminals, especially when it is known that little to none of paying victims manage to get their files back.^[2]

The best option when you want to remove Nosu ransomware is anti-malware tools that can possibly detect the threat and get rid of it. However, you should go through the system and save encrypted files, ransomware-related data on the external device. It may be possible that law enforcement or researchers will obtain decryption keys and restore those files in the future. Remember to clean the machine and repair damage with FortectIntego before any file recovery, so you can avoid getting files encrypted again.

Nosu ransom-demanding threat delivers this text after the first encryption phase of the attack:

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-7YSRbcuaMa
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:

Your personal ID:

Even though this is the newer version of the DJVU ransomware, there are many similarities. You need to know the particular file extension and identification key placed in the ransom note to determine that this is Nosu ransomware and to specify the encryption method that may be offline or online. This fact determines what you need to do next and what options you have. Nosu ransomware is the malware that cannot be decrypted easily, but you can try to store encoded files in case they can get decrypted in the future.

Decryption and file recovery options after Nosu ransomware attack

Nosu ransomware belongs to a family that is now a well-known – a positive thing for victims because anti-malware tools include each new version in the database pretty quickly. This is why we recommend relying on professional antivirus programs and their services for eliminating malware. The virus itself can be deleted from the system with such software, but encrypted data remains encrypted, and some system files still may be damaged.

For possible decryption options, there are a few factors that need to be determined with each Nosu ransomware victim:

• offline vs. online key usage;
• old vs. new variants.

When the creators of the threat use offline IDs/ keys the threat is not connecting to command and control servers while encoding files, so the encryption uses a built-in ID. This process means that many IDs end in t1 and can be easily identified. Also, Nosu ransomware victims that have been affected by the same version can get their file decrypted with the help of the released offline ID. The same key works for many people that suffered the encryption using that one key and RSA encryption method.^[3]

When online IDs get used in the process, ransomware connects to C&Cservers and generates random keys for each of the victims. Each computer has its own key, and you cannot use the same ID for many devices. Each person needs to get its own key for the decryption that is the only one generated for them. However, that can be obtained from criminals directly or after the breach, incarceration when the database becomes public.

The older versions from the same creators had more options since decryption tools got developed for them. Nearly every victim of these versions released until August 2019, got their files recovered by researchers. Unfortunately, Nosu ransomware is the newer version, so it uses the secure RSA encryption algorithm and is based on online keys that leave not many solutions for victims. It is even possible that DJVU will no longer be decrypted until the end of the service, so focus on malware elimination and file recovery ignoring the barely possible decryption talks.

Hidden codes get triggered by simple users' action

Cracked applications, p2p services, illegal pirating sites, and torrent pages can contain many more malware-related features than you may think in the first place. Freeware installations, software cracks, or license numbers, game cheats distributed from insecure sources can hide malicious ransomware code and lead to the infection directly.

Dubious links in spam email notifications or websites you get redirected to from additional scam campaigns all lead to the infiltration of malware. You cannot notice such payload droppers or even trigger the drop yourself when you click or allow any content. The code of malware can get disguised as a tool or update, so avoid any pirated software sites and choose reliable sources when getting any applications, files.

keep an eye for these red flags in suspicious emails:

• typos;
• grammar mistakes;
• misspelled company names;
• shortened links;
• financial emails from unfamiliar companies.

Tips for the proper Nosu files virus elimination

The best recommendation for any victim of the Nosu ransomware virus is to get rid of the malware as soon as possible. You need to do that, so system files and functions can still properly run. When cryptovirus affects security tools and functions like system restore there is not much left to do.

However, when you remove Nosu ransomware using anti-malware tools or security software like SpyHunter 5Combo Cleaner, Malwarebytes, you can ensure that malicious programs get terminated. Then, the only thing left to do is check system features, settings and virus damage results and recover those encrypted files.

Remember to run a cleaner or system tool to tackle the virus damage after the Nosu ransomware removal, so you cannot risk getting your data double-encrypted. Then, rely on your backups or third-party software and replace encoded files with safe ones.