Nosu is one of the ransomware, which was detected on numerous computer systems. It causes damages to the computer system which leads to becoming vulnerable to more malware attacks or infections. The purpose of Nosu ransomware is to extort money or ransom fee from the victims. Once a system is infected, it collects the valuable and personal information of the users. Encrypted files or documents will be inaccessible unless the victim pays the agreed amount to the Nosu operators.
Nosu infected files can be recognized easily because of the .nosu extension appended to it. Moreover, the virus will generate a note to victims through dropping a file named “_readme.txt” containing the message blackmailing the user and giving instructions on how to decrypt the affected files. In addition, it states how much the user should pay for it. In this case, the ransom demand is $980.
How Nosu affects the computer?
Typically, Nosu ransomware spreads through spam email campaigns. Once you open the mail or any attachments from it, Nosu ransomware will start to invade your computer system. Some victims claims that executing files downloaded from Torrent sites might have given the ransom virus full access to their computer. They are have accidentally obtained a program with the ransomware code in it. The Nosu ransomware process will begin to infect the computer system as soon as the payload file is executed. After infecting the system, the payload files will trigger malicious and questionable operations or commands. It can access and encrypt the user’s files like documents, spreadsheets, images, photos, archives, databases, and so on.
Nosu ransomware will also access the computer’s system and security settings. It may collect and record important files and information which they will encrypt and will serves as the collateral in order for user to pay declared amount in exchange of a decryption tool and private key.
How to avoid Nosu ransomware?
Since Nosu ransomware can start with just a simple email campaign, you should pay attention to the emails you are receiving. Nosu operators may pretend to be a representative from a well-known company, but check the email address because it usually contains unusual symbols. Of course, emails mostly have attached files to it. Before opening, you can scan it first using an online virus scanner. In that way, you can check if it is risky or safe to your computer system. Same diagnostics can be done to downloaded files before running an install command.
How to Remove Nosu Ransomware
Ransomware files are placed deeply into the system and on various locations, thus, thorough scanning is vital to totally remove Nosu virus. Aside from our suggested tool, you may also run your own security program.
Though affected files may be impossible to decrypt due to complexity of the encryption, you can still try recovery method like alternative tool, Shadow Explorer or Previous Version as described below.
Stage 1: Scan the Computer with Anti-Malware Tool
1. Download free anti-malware scanner called MalwareBytes Anti-Malware.
Malwarebytes Anti-Malware Download Link (this will open a new window)
2. After downloading, install the program. It may run automatically or you have to double-click on the downloaded file MB3-Setup-[version].exe.
3. Carry out the installation with default setup process.
4. At the last stage of installation process, click the Finish button. The program should launch momentarily.
5. On Malwarebytes Anti-Malware console, select Scan from the menu to see available Scan Method.
6. Next, click on Threat Scan. This is the most complete scan method that will surely find any hidden malicious objects associated to Nosu ransomware.
7. Finally, click on Start Scan begin checking the computer for malware and similar threats.
8. Once the scan has completed, the tool will display the list of detected threats. Remove all identified malicious items and restart the computer if necessary.
Stage 2: Double-check for Nosu’s leftover with Microsoft’s Malicious Software Removal Tool
1. Download the free scanner called Malicious Software Removal Tool.
Malicious Software Removal Tool Download Link (this will open a new window)
2. The tool automatically checks the operating system and suggest appropriate download version. Click on Download button to begin. Save the file to a convenient location, preferably on Desktop.
3. After downloading the file, Windows will prompt that download has completed. Click Run to start scanning for Nosu ransomware. Another option is to browse the location folder and double click on the file to run.
4. The tool will display Welcome screen, click Next. Please note the message “This tool is not a replacement for an antivirus product.” You must understand that this program is made specifically to find and remove malware, viruses, Trojans, and other harmful elements on the computer. It was not designed to protect the computer.
5. Next, you will see Scan Type. Please choose Full Scan to ensure that all Nosu ransom virus entities and other harmful files left on the computer will be found and removed. For advanced computer user, you can opt for Customized Scan, if there are other drives or folders you wanted to include in this scan.
6. Full scan may take a while, please wait for Malicious Software Removal Tool to complete the tasks. However, you may cancel the scan anytime by clicking on the Cancel button.
7. After scanning, the tool will reveal all identified threats. There may be other threats that our first scan fails to detect. Please remove/delete all detected items.
8. When removal procedure is complete, you may now close Malicious Software Removal Tool. We hope that Nosu ransomware have been completely deleted from the computer. Please restart Windows to proceed with the normal operation.
Stage 3 : Unlocking files with Nosu Decryption Tool
Tools that may decrypt files infected by Nosu is not yet available at this time. We will update this section once the tool is on hand. In the meantime, please try the options below.
Option 1: Windows Previous Version Tool
Windows Vista and Windows 7 have a feature called Previous Versions. However, this tool is only usable if restore point was made prior to Nosu ransomware infection. To use this tool and recover files affected by the virus, please follow these steps:
1. Open My Computer or Windows Explorer.
2. Right-click on the affected files or folders. From the drop-down list, please click on Restore previous versions.
3. New window will open display all backup copy of files and folders you wanted to recover. Choose the appropriate file and click on Open, Copy, or Restore. Restoring selected files overwrites the current encrypted files on the computer.
Option 2: Use ShadowExplorer to restore files encrypted by Nosu Ransomware
Just like Previous Version tool, ShadowExplorer is taking advantage of shadow copy created by Windows. This tool allows you to retrieve older version of files before it was encrypted by Nosu ransomware.
1. Download ShadowExplorer from the official web site.
2. Install the program with the default settings.
3. The program should run automatically after installation. If not, double-click on ShadowExplorer icon.
4. You can see the drop-down list on top of the console. Please select proper drive and the most recent point-in-time shadow copies of files you wish to restore prior to Nosu ransomware infection.
5. Right-click on the Drive, Folder, or File you wish to restore and click Export…
6. Lastly, ShadowExplorer will prompt for location where you want to save the copy of recovered files.