Jaff ransomware / virus (Quick Decryption Solution) - Jul 2021 update

Jaff virus Removal Guide

What is Jaff ransomware virus?

Jaff ransomware virus is a threat that can be decrypted and affected files recovered

The image of Jaff ransomware

Jaff ransomware is a crypto-malware that is distributed via Necurs botnet.[1] The virus targets at least 423 file types and encrypts them with sophisticated ciphers. During this process, the virus adds either .jaff, .wlu, or .sVn file extension after the original file extension. The virus then saves the ReadMe.bmp file and sets it as desktop wallpaper, and drops a ransom note. To determine which version of the ransomware infected your PC, look at the provided list of file extensions and ransom note names used by the virus.

Obfuscated malicious payload arrives as an email that includes a PDF attachment. Once people open this file, it loads an embedded MS Word document (.docm) that asks to enable macros in order to see the content. If a person follows the instruction, malware is dropped and activated on the system. On the affected device, the ransomware starts data encryption procedure and aims at 423 different types of files. It uses a combination of RSA and AES encryption algorithms and appends a particular extension to each of the targeted files.

Name Jaff ransomware
Type Cryptovirus, file-locker
Versions Jaff, Wlu, Svn
Ransom note !!!!README_FOR_SAVE FILES.txt, !!!SAVE YOUR FILES.bmp, !!!!!SAVE YOUR FILES!!!!.txt, !!!SAVE YOUR FILES!.bmp, README_TO_DECRYPTl.txt, README_TO_DECRYPTl.bmp, README_TO_DECRYPT.html, ReadMe.txt, ReadMe.bmp, and ReadMe.html;
File appendix .jaff; .wlu; .sVn
Distribution Deceptive online material, malicious file attachments, pirating platforms
Removal Anti-malware tools are the best when dealing with such infections because those apps can find all pieces related to virus. As for damaged parts of the machine – run FortectIntego

Following data encryption, it drops ransom notes filled with information about the ransomware attack. The image file (BMP) is set as the affected computer’s wallpaper that informs about Jaff Decryptor System. The other two files include a ransom-demanding message where victims are asked to transfer 2 Bitcoins for data recovery. However, purchasing decryptors from cybercriminals may end up with money loss as well.

After a ransomware attack, you should focus on virus removal. While malware resides on the system, your computer, as well as your privacy, is at risk. Therefore you must remove the ransomware with the help of reputable malware removal programs such as SpyHunter 5Combo Cleaner, Malwarebytes. Only then you should look up data recovery solutions.

IMPORTANT. Victims infected with three initial Jaff versions – .wlu, .jaff, and .sVn file extension viruses can now decrypt files for FREE, thanks to Kaspersky Team. To decrypt files, download the decryption tool using the link provided down in data recovery instructions and let it restore all your files for free.

The illustration of Jaff ransomware virusThe virus is executed on the system as soon as a person opens the malicious email attachment.

Jaff ransomware resembles Locky and Dridex viruses because it uses the same Necurs malspam[2] as the main distribution strategy. However, the structure of the malware indicates that it is not related to these cyber infections, although the payment page is almost identical to Locky's. Cybercriminals just adapted few features of successful ransomware projects.

As we already mentioned, the infected email has an attached PDF file that opens a DOCM file. Once victims click the “Enable Content” button, they activate the malicious script placed in that file and it downloads various files that are necessary to execute and run this malware.

When a file-encrypting virus is executed, it connects to its Command & Control server and informs about a newly attacked device. The C2 server responds with the word “Created” and malware starts the data encryption procedure. It only stays away from system files and other important data that is necessary for running the computer.

Jaff virus is also designed to delete Shadow Volume Copies of the targeted files by executing vssadmin.exe delete shadows /all /Quiet command in order to make data recovery nearly impossible without a particular decryption key. The malware drops ransom notes to each folder that has affected files, where criminals explain how to obtain a decryption key.

Ransom-demanding message also includes a unique victim’s ID and provides a link to the payment website, which can be accessed only using the TOR browser. It includes information on how to buy Bitcoins and how to transfer them to the provided address in order to obtain the decryption key. Once Jaff ransomware has been spotted, it asked to pay 1.82 BTS; however, the newest versions demand to transfer 2 BTC.[3]

Unfortunately, there are no guarantees that cybercriminals will give you access to the Decryptor. They are interested in getting your money only. Thus, you should not risk losing $3000 and having business with shady people. However, if you have backups, you can call yourself lucky because it’s the only way to restore your files at the moment. Otherwise, chances to get back your files are low, but this situation should not motivate you to pay the ransom.

Instead of risking losing few thousand dollars, you should focus on cyber threat removal procedures. When your computer is virus-free, you can try alternative recovery methods and restore at least some of your files or wait until the official decryptor is released.

Image of new Jaff variantAn image of the new Jaff ransom note

Detailed analysis of Jaff ransomware distribution methods

Jaff virus uses Necurs botnet to spread malicious spam emails with infected PDF documents. As we already mentioned, this technique has been used in the distribution of Locky. The phishing email has a subject line that has one of these words that are followed by the random numbers, for instance, Copy_0504747, PDF_57583, Scan_15467085, Your Invoice # 87871, or File_2227958. Such letters contain a PDF attachment named “nm.pdf” and might provide numerous reasons why users have to open it.

For instance, one spam campaign simply asks to print two copies of the file.[4] If a user is tricked into opening it, the PDF file asks to open an embedded DOCM file. Depending on what version of PDF reader is installed on the attacked device, the file might open a DOCM file automatically, or it might ask a user to open it.

Once the Word file is opened, it delivers a message that this document is protected and the user needs to click “Enable Content” button. The button hides a malicious macro command which is designed to contact a malicious domain to download ransomware-related files to execute the Decryption System.

Thus, if you do not expect to receive any document or file, you should not open any suspicious email attachments. Before opening the attached files, you need to make sure that you know the sender and can trust him or her.[5] Otherwise, delete such email immediately.

The explained technique was used to push .jaff and .wlu ransomware variants. However, since June 13, 2017, the ransomware developers slightly altered the distribution technique and started pushing the malspam containing the .sVn file extension virus. This time the malicious actors use such and similar subject lines for the malicious messages: Invoice PIS1314074, Invoice PIS8938690.

The emails contain a ZIP file entitled invoicepis8938690.zip, invoicepis9587975.zip, or similarly. This ZIP attachment contains another ZIP attachment called HF4YIDIIL.zip, B9UHRNO5.zip, or similarly. Extracting the second folder places a Windows Script File on the system called identically as the previous ZIP folder – B9UHRNO5.wsf, HF4YIDIIL.wsf, and similarly. Launching the .wsf file activates a script that connects to a malicious domain and downloads the malicious payload.

Jaff ransomware might also be distributed via social networks and file-sharing sites. Thus, you might receive a link from a friend (or unfamiliar person) that suggests watching a video or picture. Before clicking on such links, you should always make sure that it’s safe to open. For instance, you can ask your friend whether he or she sent it or not.

What is more, malware might also be promoted as a useful program on various P2P networks. If you need to install a particular program, you should avoid using unknown download sites. Always choose official developers’ or publishers’ websites in order to prevent the installation of malicious programs.

Update May 2017: New design and .wlu file extensions used

The second wave of the virus has hit the web, and this time the malware seems to have undergone some adjustments. First of all, the latest virus version looks completely different from the original. The criminals have labeled this new virus “Jaff Decryptor” instead of the original “ decryptor system” and made changes to the overall design of the ransom note and ransom payment site.

The malware now looks much more professional than it appeared in the beginning. Besides, the changes were not carried out only on the visual level. The virus has undergone modifications in its source code as well: the new .WLU extension has been added to the list of unusual file endings that this virus appends to indicate encrypted files.

What hasn’t changed, though, is the method of ransomware distribution. It still spreads around through malicious spam campaigns and tries to trick users into downloading it on their computers as a supposed invoice file. The subjects of these files will feature titles such as Copy of Invoice 99483713 or Invoice(58-0710). Please note that the numbers may change which each individual attack. So, be careful and don’t download any files received from unfamiliar senders or generally untrusted sources.

Update June 2017: New variant uses .sVn extension

“New month, new extension” seems to be the motto of the Jaff ransomware developers. The researchers have found a new variant of ransomware that appends encrypted files with .sVn extensions. The discovery has been made by Derek Knight, a security researcher who has been investigating spoofed spam emails supposedly received from copy machines in the companies of its potential victims.

These emails arrive under subject names such Message from KM_C224e. Inside them comes an attached file called SKM_C224e54955163156.zip which carries a malicious executable. When activated the executable would download the virus on the computer and start encrypting files, marking the already affected documents with .sVn extensions. New extensions in ransomware typically indicate a new virus version.

In this case, this is justified by the renamed ransom note and image which replaces the desktop background after the ransomware infection. Now, these files are called !!!!README_FOR_SAVE FILES.txt and !!!SAVE YOUR FILES.bmp. Unfortunately, this virus version is not decryptable either. However, the recovery methods below are always there for you to try out.

Update June 15, 2017: Jaff ransomware decryptor is available

The infamous ransomware that seemed to be undefeatable at first appeared to be not as sophisticated as it seemed at first. Of course, it did take a lot of time and patience for Kaspersky experts to analyze the samples of the ransomware and go step-by-step to create an all-in-one decryptor for Jaff file virus family.

The new tool was released on June 14, 2017, and it is capable of restoring .wlu, .jaff, .sVn file extension files back to their original condition. Remember that before using this tool, you must get rid of the ransomware and all of its components. Use a powerful malware remover to eliminate the ransomware before using the decryptor.

Remove Jaff ransomware completely before running the decryption tool

The only safe way to remove the infection from the device is to run a full system scan with a reputable malware removal program. We want to discourage you from trying to delete ransomware manually because it might have injected legitimate system processes and modified Windows Registry.

Thus, you can easily cause more damage by unintentionally stopping important processes or deleting crucial entries. Do not hesitate and install Malwarebytes, SpyHunter 5Combo Cleaner, or other malware removal programs.

If you cannot do that, restart your computer to the Safe Mode with networking as shown in the instructions below. Then you should be able to install a security program and perform automatic Jaff virus removal. Once the computer is virus-free, you can restore your files from backups or try alternative recovery solutions.

Kaspersky Labs have updated their RakhniDecryptor, a tool capable of decrypting various types of ransomware. Download RakhniDecryptor and make sure you have the version (or higher).

  • Click Start scan and select a particular folder to find files locked by the ransomware.
  • The decryptor will ask you to select a ransom note. Once you select it, hit the Open button and then wait until the decryptor decrypts files. Be patient – this might take a while.
  • Repeat with all folders that contain important encrypted files.

do it now!
Fortect Happiness
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Compatible with Microsoft Windows Compatible with macOS
What to do if failed?
If you failed to fix virus damage using Fortect Intego, submit a question to our support team and provide as much details as possible.
Fortect Intego has a free limited scanner. Fortect Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Fortect, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

Getting rid of Jaff virus. Follow these steps

Isolate the infected computer

Some ransomware strains aim to infect not only one computer but hijack the entire network. As soon as one of the machines is infected, malware can spread via network and encrypt files everywhere else, including Network Attached Storage (NAS) devices. If your computer is connected to a network, it is important to isolate it to prevent re-infection after ransomware removal is complete.

The easiest way to disconnect a PC from everything is simply to plug out the ethernet cable. However, in the corporate environment, this might be extremely difficult to do (also would take a long time). The method below will disconnect from all the networks, including local and the internet, isolating each of the machines involved.

  • Type in Control Panel in Windows search and press Enter
  • Go to Network and Internet Network and internet
  • Click Network and Sharing Center Network and internet 2
  • On the left, pick Change adapter settings Network and internet 3
  • Right-click on your connection (for example, Ethernet), and select Disable Network and internet 4
  • Confirm with Yes.

If you are using some type of cloud storage you are connected to, you should disconnect from it immediately. It is also advisable to disconnect all the external devices, such as USB flash sticks, external HDDs, etc. Once the malware elimination process is finished, you can connect your computers to the network and internet, as explained above, but by pressing Enable instead.

Scan your system with anti-malware

If you are a victim of ransomware, you should employ anti-malware software for its removal. Some ransomware can self-destruct after the file encryption process is finished. Even in such cases, malware might leave various data-stealing modules or could operate in conjunction with other malicious programs on your device. 

SpyHunter 5Combo Cleaner or Malwarebytes can detect and eliminate all ransomware-related files, additional modules, along with other viruses that could be hiding on your system. The security software is really easy to use and does not require any prior IT knowledge to succeed in the malware removal process.

Repair damaged system components

Once a computer is infected with malware, its system is changed to operate differently. For example, an infection can alter the Windows registry database, damage vital bootup and other sections, delete or corrupt DLL files, etc. Once a system file is damaged by malware, antivirus software is not capable of doing anything about it, leaving it just the way it is. Consequently, users might experience performance, stability, and usability issues, to the point where a full Windows reinstall is required.

Therefore, we highly recommend using a one-of-a-kind, patented technology of FortectIntego repair. Not only can it fix virus damage after the infection, but it is also capable of removing malware that has already broken into the system thanks to several engines used by the program. Besides, the application is also capable of fixing various Windows-related issues that are not caused by malware infections, for example, Blue Screen errors, freezes, registry errors, damaged DLLs, etc.

  • Download the application by clicking on the link above
  • Click on the ReimageRepair.exe
    Reimage download
  • If User Account Control (UAC) shows up, select Yes
  • Press Install and wait till the program finishes the installation process Reimage installation
  • The analysis of your machine will begin immediately Reimage scan
  • Once complete, check the results – they will be listed in the Summary
  • You can now click on each of the issues and fix them manually
  • If you see many problems that you find difficult to fix, we recommend you purchase the license and fix them automatically. Reimage results

By employing FortectIntego, you would not have to worry about future computer issues, as most of them could be fixed quickly by performing a full system scan at any time. Most importantly, you could avoid the tedious process of Windows reinstallation in case things go very wrong due to one reason or another.

Restore Windows "hosts" file to its original state

Some ransomware might modify Windows hosts file in order to prevent users from accessing certain websites online. For example, Djvu ransomware variants add dozens of entries containing URLs of security-related websites, such as 2-spyware.com. Each of the entries means that users will not be able to access the listed web addresses and will receive an error instead.

Here's an example of “hosts” file entries that were injected by ransomware:

Hosts file

In order to restore your ability to access all websites without restrictions, you should either delete the file (Windows will automatically recreate it) or remove all the malware-created entries. If you have never touched the “hosts” file before, you should simply delete it by marking it and pressing Shift + Del on your keyboard. For that, navigate to the following location:


Delete Windows "hosts" file

Restore files using data recovery software

Since many users do not prepare proper data backups prior to being attacked by ransomware, they might often lose access to their files permanently. Paying criminals is also very risky, as they might not fulfill the promises and never send back the required decryption tool.

While this might sound terrible, not all is lost – data recovery software might be able to help you in some situations (it highly depends on the encryption algorithm used, whether ransomware managed to complete the programmed tasks, etc.). Since there are thousands of different ransomware strains, it is immediately impossible to tell whether third-party software will work for you.

Therefore, we suggest trying regardless of which ransomware attacked your computer. Before you begin, several pointers are important while dealing with this situation:

  • Since the encrypted data on your computer might permanently be damaged by security or data recovery software, you should first make backups of it – use a USB flash drive or another storage.
  • Only attempt to recover your files using this method after you perform a scan with anti-malware software.

Install data recovery software

  1. Download Data Recovery Pro.
  2. Double-click the installer to launch it.
    Launch installer
  3. Follow on-screen instructions to install the software. Install program
  4. As soon as you press Finish, you can use the app.
  5. Select Everything or pick individual folders where you want the files to be recovered from. Select what to recover
  6. Press Next.
  7. At the bottom, enable Deep scan and pick which Disks you want to be scanned. Select Deep scan
  8. Press Scan and wait till it is complete. Scan
  9. You can now pick which folders/files to recover – don't forget you also have the option to search by the file name!
  10. Press Recover to retrieve your files. Recover files

Create data backups to avoid file loss in the future

One of the many countermeasures for home users against ransomware is data backups. Even if your Windows get corrupted, you can reinstall everything from scratch and retrieve files from backups with minimal losses overall. Most importantly, you would not have to pay cybercriminals and risk your money as well.

Therefore, if you have already dealt with a ransomware attack, we strongly advise you to prepare backups for future use. There are two options available to you:

  • Backup on a physical external drive, such as a USB flash drive or external HDD.
  • Use cloud storage services.

The first method is not that convenient, however, as backups need to constantly be updated manually – although it is very reliable. Therefore, we highly advise choosing cloud storage instead – it is easy to set up and efficient to sustain. The problem with it is that storage space is limited unless you want to pay for the subscription.

Using Microsoft OneDrive

OneDrive is a built-in tool that comes with every modern Windows version. By default, you get 5 GB of storage that you can use for free. You can increase that storage space, but for a price. Here's how to setup backups for OneDrive:

  1. Click on the OneDrive icon within your system tray.
  2. Select Help & Settings > Settings.
    Go to OneDrive settings
  3. If you don't see your email under the Account tab, you should click Add an account and proceed with the on-screen instructions to set yourself up.
    Add OneDrive account
  4. Once done, move to the Backup tab and click Manage backup.
    Manage backup
  5. Select Desktop, Documents, and Pictures, or a combination of whichever folders you want to backup.
  6. Press Start backup.
    Pick which folders to sync

After this, all the files that are imported into the above-mentioned folders will be automatically backed for you. If you want to add other folders or files, you have to do that manually. For that, open File Explorer by pressing Win + E on your keyboard, and then click on the OneDrive icon. You should drag and drop folders you want to backup (or you can use Copy/Paste as well).

Using Google Drive

Google Drive is another great solution for free backups. The good news is that you get as much as 15GB for free by choosing this storage. There are also paid versions available, with significantly more storage to choose from.

You can access Google Drive via the web browser or use a desktop app you can download on the official website. If you want your files to be synced automatically, you will have to download the app, however.

  1. Download the Google Drive app installer and click on it.
    Install Google Drive app
  2. Wait a few seconds for it to be installed. Complete installation
  3. Now click the arrow within your system tray – you should see Google Drive icon there, click it once.
    Google Drive Sign in
  4. Click Get Started. Backup and sync
  5. Enter all the required information – your email/phone, and password. Enter email/phone
  6. Now pick what you want to sync and backup. You can click on Choose Folder to add additional folders to the list.
  7. Once done, pick Next. Choose what to sync
  8. Now you can select to sync items to be visible on your computer.
  9. Finally, press Start and wait till the sync is complete. Your files are now being backed up.

Manual removal using Safe Mode

Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.

Step 1. Access Safe Mode with Networking

Manual malware removal should be best performed in the Safe Mode environment. 

Windows 7 / Vista / XP
  1. Click Start > Shutdown > Restart > OK.
  2. When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. – it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
  3. Select Safe Mode with Networking from the list. Windows 7/XP
Windows 10 / Windows 8
  1. Right-click on Start button and select Settings.
  2. Scroll down to pick Update & Security.
    Update and security
  3. On the left side of the window, pick Recovery.
  4. Now scroll down to find Advanced Startup section.
  5. Click Restart now.
  6. Select Troubleshoot. Choose an option
  7. Go to Advanced options. Advanced options
  8. Select Startup Settings. Startup settings
  9. Press Restart.
  10. Now press 5 or click 5) Enable Safe Mode with Networking. Enable safe mode

Step 2. Shut down suspicious processes

Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Click on More details.
    Open task manager
  3. Scroll down to Background processes section, and look for anything suspicious.
  4. Right-click and select Open file location.
    Open file location
  5. Go back to the process, right-click and pick End Task.
    End task
  6. Delete the contents of the malicious folder.

Step 3. Check program Startup

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Go to Startup tab.
  3. Right-click on the suspicious program and pick Disable.

Step 4. Delete virus files

Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:

  1. Type in Disk Cleanup in Windows search and press Enter.
    Disk cleanup
  2. Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
  3. Scroll through the Files to delete list and select the following:

    Temporary Internet Files
    Recycle Bin
    Temporary files

  4. Pick Clean up system files.
    Delete temp files
  5. You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):


After you are finished, reboot the PC in normal mode.

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from Jaff and other ransomwares, use a reputable anti-spyware, such as FortectIntego, SpyHunter 5Combo Cleaner or Malwarebytes

How to prevent from getting ransomware

Choose a proper web browser and improve your safety with a VPN tool

Online spying has got momentum in recent years and people are getting more and more interested in how to protect their privacy online. One of the basic means to add a layer of security – choose the most private and secure web browser. Although web browsers can't grant full privacy protection and security, some of them are much better at sandboxing, HTTPS upgrading, active content blocking, tracking blocking, phishing protection, and similar privacy-oriented features. However, if you want true anonymity, we suggest you employ a powerful Private Internet Access VPN – it can encrypt all the traffic that comes and goes out of your computer, preventing tracking completely.


Lost your files? Use data recovery software

While some files located on any computer are replaceable or useless, others can be extremely valuable. Family photos, work documents, school projects – these are types of files that we don't want to lose. Unfortunately, there are many ways how unexpected data loss can occur: power cuts, Blue Screen of Death errors, hardware failures, crypto-malware attack, or even accidental deletion.

To ensure that all the files remain intact, you should prepare regular data backups. You can choose cloud-based or physical copies you could restore from later in case of a disaster. If your backups were lost as well or you never bothered to prepare any, Data Recovery Pro can be your only hope to retrieve your invaluable files.

About the author
Alice Woods
Alice Woods - Likes to teach users about virus prevention

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