Remove NOSU Ransomware Virus (2023 Guide)

NOSU ransomware blocks access to your own files

NOSU ransomware is a file-encrypting virus which is the 197th version of STOP/DJVU malware. Once installed on the system, it starts applying asymmetric encryption on victim’s files stored on the computer, computer network or connected devices. Each encrypted file gets marked with .nosu file extension. The virus removes all means of data recovery possibilities immediately, for example, it deletes system restore points and leaves no traces of private decryption key. Next, it creates _readme.txt note with instructions on paying the ransom to cybercriminals ($490-$980 in Bitcoin). To get further information, the attackers suggest contacting them via helpmanager@firemail.cc or helpmanager@iran.ir (same email used in the KODC ransomware variant).

NOSU file virus is extremely dangerous because it corrupts important personal documents, videos, databases and other files which are essential to the victim’s work or personal life. What is even worse, the ransomware tends to install AZORULT password-stealing Trojan on the system. This malicious virus can extract all saved passwords from your browsers and possibly track your keystrokes. Therefore, a removal of such malware is essential.

The ransom note threatens to pay the ransom ASAP

The ransom note created by NOSU virus tells the victim that all important files have been encrypted. This is true – and the attackers are the only ones who have the decryption keys. To get the decryption key, the attackers suggest paying the ransom, which can cost $490 if paid within 3 days, or $980 if later. First of all, paying the cybercriminals is NEVER a recommended practice as they may never return access to your files; second, such sum of money is simply ridiculous.

The note explains that the victim must write to helpmanager@firemail.cc or, if no reply within 6 hours, try writing to alternative address, helpmanager@iran.ir. The attackers are quick to respond when it comes to convinving the victim to pay up. However, they might vanish once the money is in their cryptocurrency wallet.

The note also explains what is victim’s personal ID – however, there is another file on the computer containing ACTUAL ID, or IDs. Now, let us get into the ID matter further.

Free decryption possibilities

NOSU ransomware, just like the previous versions of STOP/DJVU, tend to use online OR offline keys to encrypt victims files. This, in fact, determines your chances to recover files for free. See instructions below to figure out your .nosu extension data recovery chances.

In order to figure out the real victim’s IDs, one must go to C:/SystemID/ and find a file called SystemID.txt here.

If you are victim of NOSU ransomware virus, you should check the IDs stored in that file and see if any of these IDs end in t1. If so, it means that some part of your data was encrypted with an offline encryption key, which means that there are chances to restore such data for free. For the IDs ending in any other character combination, free decryption is impossible. You can learn more about that here – STOP decrypter guide.

Threat Summary

Name	NOSU ransomware virus
Type	File-encrypting computer virus
Origins	STOP/DJVU (197th version)
Targeted systems	Windows
Behavior	Encrypts files on the computer or network and connected devices, installs AZORULT Trojan
Extension	Appends .nosu file extension to files
Ransom note	_readme.txt
Ransom demand	$490-$980
Emails	helpmanager@firemail.cc or helpmanager@iran.ir
Distribution	Spreads alongside illegal online downloads such as software cracks or keygens
Decryption tools	STOP Decryptor doesn’t support this extension at the moment
Removal	Remove using antivirus while in Safe Mode (see instructions below)

STOP ransomware variants spread alongside illegal software activators

You might install NOSU file virus or other DJVU ransomware variant if you attempt to activate paid software versions illegally. For example, people often to try to obtain software licensed versions via software cracks, key generators (also known as keygens) or other activation tools such as KMSPico. You must keep in mind that such tools are cybercriminals’ go-to when it comes to malware distribution.

They simply compress their illegal programs alongside such tools, or even name their viruses accordingly to deceive the unsuspecting victims. What is even worse is that people tend to ignore security software warnings NOT to open such illegal tools. Once launched, the malware infects the computer rapidly.

How to remove NOSU ransomware virus effectively

NOSU ransomware removal is your top priority after becoming a victim to such cyber attack. You must delete all remains of the file-encrypting virus as well as Azorult’s files, too. Doing so manually can be tricky. Therefore, we recommend using a trustworthy antivirus or anti-malware when in Safe Mode for the elimination of malicious software traces.

Remove NOSU Ransomware Virus using instructions provided below. This will ensure a thorough cleanse of your computer system. Next, we suggest changing ALL of your passwords immediately. Finally, start searching for data backups – but do not plug these external devices to your computer unless the malware is completely gone. Otherwise, your backup might get corrupted, too.

OUR GEEKS RECOMMEND

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:

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Alternative software recommendations

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